81240646032 has 960 divisors, whose sum is σ = 306830361600. Its totient is φ = 20379340800.

The previous prime is 81240645989. The next prime is 81240646033. The reversal of 81240646032 is 23064604218.

81240646032 is a `hidden beast` number, since 8 + 1 + 2 + 4 + 0 + 646 + 0 + 3 + 2 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (81240646033) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 804362782 + ... + 804362882.

It is an arithmetic number, because the mean of its divisors is an integer number (319614960).

Almost surely, 2^81240646032 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 81240646032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153415180800).

81240646032 is an abundant number, since it is smaller than the sum of its proper divisors (225589715568).

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

81240646032 is a wasteful number, since it uses less digits than its factorization.

81240646032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 81240646032 in words is "eighty-one billion, two hundred forty million, six hundred forty-six thousand, thirty-two".