79339821 has 24 divisors (see below), whose sum is σ = 117261312. Its totient is φ = 47678400.

The previous prime is 79339789. The next prime is 79339829. The reversal of 79339821 is 12893397.

79339821 = 749² + 750² + ... + 869².

It is not a de Polignac number, because 79339821 - 2⁵ = 79339789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79339829) 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 23 ways as a sum of consecutive naturals, for example, 45241 + ... + 46961.

It is an arithmetic number, because the mean of its divisors is an integer number (4885888).

Almost surely, 2^79339821 is an apocalyptic number.

It is an amenable number.

79339821 is a deficient number, since it is larger than the sum of its proper divisors (37921491).

79339821 is a wasteful number, since it uses less digits than its factorization.

79339821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873 (or 1862 counting only the distinct ones).

The product of its digits is 81648, while the sum is 42.

The square root of 79339821 is about 8907.2903287139. The cubic root of 79339821 is about 429.6984021767.

It can be divided in two parts, 79 and 339821, that added together give a triangular number (339900 = T₈₂₄).

The spelling of 79339821 in words is "seventy-nine million, three hundred thirty-nine thousand, eight hundred twenty-one".