81870492 has 48 divisors (see below), whose sum is σ = 214042752. Its totient is φ = 24137280.

The previous prime is 81870469. The next prime is 81870493. The reversal of 81870492 is 29407818.

It is a self number, because there is not a number n which added to its sum of digits gives 81870492.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81870493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3498 + ... + 13265.

It is an arithmetic number, because the mean of its divisors is an integer number (4459224).

Almost surely, 2^81870492 is an apocalyptic number.

It is an amenable number.

81870492 is an abundant number, since it is smaller than the sum of its proper divisors (132172260).

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

81870492 is a wasteful number, since it uses less digits than its factorization.

81870492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16818 (or 16816 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 81870492 is about 9048.2314294010. The cubic root of 81870492 is about 434.2193105379.

The spelling of 81870492 in words is "eighty-one million, eight hundred seventy thousand, four hundred ninety-two".