79721907 has 4 divisors (see below), whose sum is σ = 106295880. Its totient is φ = 53147936.

The previous prime is 79721903. The next prime is 79721923. The reversal of 79721907 is 70912797.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 79721907 - 2² = 79721903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (79721903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13286982 + ... + 13286987.

It is an arithmetic number, because the mean of its divisors is an integer number (26573970).

Almost surely, 2^79721907 is an apocalyptic number.

79721907 is a deficient number, since it is larger than the sum of its proper divisors (26573973).

79721907 is a wasteful number, since it uses less digits than its factorization.

79721907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26573972.

The product of its (nonzero) digits is 55566, while the sum is 42.

The square root of 79721907 is about 8928.7125051712. The cubic root of 79721907 is about 430.3870806912.

The spelling of 79721907 in words is "seventy-nine million, seven hundred twenty-one thousand, nine hundred seven".