79921281 has 16 divisors (see below), whose sum is σ = 117653760. Its totient is φ = 47851920.

The previous prime is 79921273. The next prime is 79921327. The reversal of 79921281 is 18212997.

It is not a de Polignac number, because 79921281 - 2³ = 79921273 is a prime.

It is a super-2 number, since 2×79921281² = 12774822313361922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (79921211) 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, 11851 + ... + 17328.

It is an arithmetic number, because the mean of its divisors is an integer number (7353360).

Almost surely, 2^79921281 is an apocalyptic number.

It is an amenable number.

79921281 is a deficient number, since it is larger than the sum of its proper divisors (37732479).

79921281 is a wasteful number, since it uses less digits than its factorization.

79921281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29276.

The product of its digits is 18144, while the sum is 39.

The square root of 79921281 is about 8939.8703010726. The cubic root of 79921281 is about 430.7455625054.

The spelling of 79921281 in words is "seventy-nine million, nine hundred twenty-one thousand, two hundred eighty-one".