61636320 has 144 divisors (see below), whose sum is σ = 219596832. Its totient is φ = 15713280.

The previous prime is 61636319. The next prime is 61636321. The reversal of 61636320 is 2363616.

61636320 is a `hidden beast` number, since 6 + 1 + 636 + 3 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (61636319) and next prime (61636321).

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61636321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32190 + ... + 34050.

It is an arithmetic number, because the mean of its divisors is an integer number (1524978).

Almost surely, 2^61636320 is an apocalyptic number.

61636320 is a gapful number since it is divisible by the number (60) 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 61636320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109798416).

61636320 is an abundant number, since it is smaller than the sum of its proper divisors (157960512).

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

61636320 is a wasteful number, since it uses less digits than its factorization.

61636320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905 (or 1894 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 61636320 is about 7850.8802054292. The cubic root of 61636320 is about 395.0137686810.

Adding to 61636320 its reverse (2363616), we get a palindrome (63999936).

The spelling of 61636320 in words is "sixty-one million, six hundred thirty-six thousand, three hundred twenty".