79908821 has 4 divisors (see below), whose sum is σ = 80518944. Its totient is φ = 79298700.

The previous prime is 79908817. The next prime is 79908827. The reversal of 79908821 is 12880997.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79908821 - 2² = 79908817 is a prime.

It is a super-2 number, since 2×79908821² = 12770839347220082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79908827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 304865 + ... + 305126.

It is an arithmetic number, because the mean of its divisors is an integer number (20129736).

Almost surely, 2^79908821 is an apocalyptic number.

It is an amenable number.

79908821 is a deficient number, since it is larger than the sum of its proper divisors (610123).

79908821 is a wasteful number, since it uses less digits than its factorization.

79908821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610122.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 79908821 is about 8939.1733957900. The cubic root of 79908821 is about 430.7231764417.

The spelling of 79908821 in words is "seventy-nine million, nine hundred eight thousand, eight hundred twenty-one".