81515260992 has 224 divisors, whose sum is σ = 243165441024. Its totient is φ = 23885568000.

The previous prime is 81515260927. The next prime is 81515260993. The reversal of 81515260992 is 29906251518.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (81515260993) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9167973 + ... + 9176859.

Almost surely, 2^81515260992 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 81515260992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121582720512).

81515260992 is an abundant number, since it is smaller than the sum of its proper divisors (161650180032).

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

81515260992 is a wasteful number, since it uses less digits than its factorization.

81515260992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9057 (or 9047 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 48.

The spelling of 81515260992 in words is "eighty-one billion, five hundred fifteen million, two hundred sixty thousand, nine hundred ninety-two".