79921947 has 32 divisors (see below), whose sum is σ = 129682944. Its totient is φ = 42739200.

The previous prime is 79921927. The next prime is 79921967. The reversal of 79921947 is 74912997.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (79921927) and next prime (79921967).

It is not a de Polignac number, because 79921947 - 2⁷ = 79921819 is a prime.

It is a super-2 number, since 2×79921947² = 12775035224541618, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 79921896 and 79921905.

It is not an unprimeable number, because it can be changed into a prime (79921927) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74797 + ... + 75857.

It is an arithmetic number, because the mean of its divisors is an integer number (4052592).

Almost surely, 2^79921947 is an apocalyptic number.

79921947 is a deficient number, since it is larger than the sum of its proper divisors (49760997).

79921947 is a wasteful number, since it uses less digits than its factorization.

79921947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1299.

The product of its digits is 285768, while the sum is 48.

The square root of 79921947 is about 8939.9075498575. The cubic root of 79921947 is about 430.7467589983.

The spelling of 79921947 in words is "seventy-nine million, nine hundred twenty-one thousand, nine hundred forty-seven".