81791590028 has 12 divisors (see below), whose sum is σ = 147752549952. Its totient is φ = 39576575760.

The previous prime is 81791589973. The next prime is 81791590037. The reversal of 81791590028 is 82009519718.

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, 329804675 + ... + 329804922.

It is an arithmetic number, because the mean of its divisors is an integer number (12312712496).

Almost surely, 2^81791590028 is an apocalyptic number.

It is an amenable number.

81791590028 is a deficient number, since it is larger than the sum of its proper divisors (65960959924).

81791590028 is a wasteful number, since it uses less digits than its factorization.

81791590028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659609632 (or 659609630 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 50.

The spelling of 81791590028 in words is "eighty-one billion, seven hundred ninety-one million, five hundred ninety thousand, twenty-eight".