81012992 has 36 divisors (see below), whose sum is σ = 168752640. Its totient is φ = 38742528.

The previous prime is 81012961. The next prime is 81013003. The reversal of 81012992 is 29921018.

It is a happy number.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 992 + ... + 12767.

Almost surely, 2^81012992 is an apocalyptic number.

It is an amenable number.

81012992 is an abundant number, since it is smaller than the sum of its proper divisors (87739648).

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

81012992 is a wasteful number, since it uses less digits than its factorization.

81012992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13798 (or 13784 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 81012992 is about 9000.7217488377. The cubic root of 81012992 is about 432.6980028264.

The spelling of 81012992 in words is "eighty-one million, twelve thousand, nine hundred ninety-two".