81599519232 has 1200 divisors, whose sum is σ = 322414114176. Its totient is φ = 20072448000.

The previous prime is 81599519231. The next prime is 81599519233. The reversal of 81599519232 is 23291599518.

It is a happy number.

81599519232 is a `hidden beast` number, since 8 + 1 + 5 + 99 + 519 + 2 + 32 = 666.

It is an interprime number because it is at equal distance from previous prime (81599519231) and next prime (81599519233).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (81599519231) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 807915982 + ... + 807916082.

Almost surely, 2^81599519232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81599519232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161207057088).

81599519232 is an abundant number, since it is smaller than the sum of its proper divisors (240814594944).

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

81599519232 is a wasteful number, since it uses less digits than its factorization.

81599519232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183 (or 147 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 54.

The spelling of 81599519232 in words is "eighty-one billion, five hundred ninety-nine million, five hundred nineteen thousand, two hundred thirty-two".