31801801536 has 336 divisors, whose sum is σ = 99887428368. Its totient is φ = 9633792000.

The previous prime is 31801801489. The next prime is 31801801571. The reversal of 31801801536 is 63510810813.

31801801536 is a `hidden beast` number, since 31 + 80 + 18 + 0 + 1 + 536 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 2066247936 + 29735553600 = 45456^2 + 172440^2 .

It is a super-2 number, since 2×31801801536² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 31801801536.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45365986 + ... + 45366686.

It is an arithmetic number, because the mean of its divisors is an integer number (297284013).

Almost surely, 2^31801801536 is an apocalyptic number.

31801801536 is a gapful number since it is divisible by the number (36) 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 31801801536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49943714184).

31801801536 is an abundant number, since it is smaller than the sum of its proper divisors (68085626832).

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

31801801536 is a wasteful number, since it uses less digits than its factorization.

31801801536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890 (or 877 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 31801801536 in words is "thirty-one billion, eight hundred one million, eight hundred one thousand, five hundred thirty-six".