81140392 has 16 divisors (see below), whose sum is σ = 157046400. Its totient is φ = 39261360.

The previous prime is 81140369. The next prime is 81140419. The reversal of 81140392 is 29304118.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81140392.

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, 163342 + ... + 163837.

It is an arithmetic number, because the mean of its divisors is an integer number (9815400).

Almost surely, 2^81140392 is an apocalyptic number.

It is an amenable number.

81140392 is a deficient number, since it is larger than the sum of its proper divisors (75906008).

81140392 is a wasteful number, since it uses less digits than its factorization.

81140392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327216 (or 327212 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 81140392 is about 9007.7961788664. The cubic root of 81140392 is about 432.9247024900.

The spelling of 81140392 in words is "eighty-one million, one hundred forty thousand, three hundred ninety-two".