36581220 has 168 divisors, whose sum is σ = 124680696. Its totient is φ = 8957952.

The previous prime is 36581219. The next prime is 36581221. The reversal of 36581220 is 2218563.

36581220 is a `hidden beast` number, since 3 + 658 + 1 + 2 + 2 + 0 = 666.

36581220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (36581219) and next prime (36581221).

It can be written as a sum of positive squares in 4 ways, for example, as 2916 + 36578304 = 54^2 + 6048^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36581221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 189444 + ... + 189636.

It is an arithmetic number, because the mean of its divisors is an integer number (742147).

Almost surely, 2^36581220 is an apocalyptic number.

36581220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 36581220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62340348).

36581220 is an abundant number, since it is smaller than the sum of its proper divisors (88099476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

36581220 is a wasteful number, since it uses less digits than its factorization.

36581220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 36581220 is about 6048.2410666242. The cubic root of 36581220 is about 331.9602337816.

Adding to 36581220 its reverse (2218563), we get a palindrome (38799783).

The spelling of 36581220 in words is "thirty-six million, five hundred eighty-one thousand, two hundred twenty".