79230821 has 4 divisors (see below), whose sum is σ = 79359852. Its totient is φ = 79101792.

The previous prime is 79230803. The next prime is 79230847. The reversal of 79230821 is 12803297.

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

It can be written as a sum of positive squares in 2 ways, for example, as 22905796 + 56325025 = 4786^2 + 7505^2 .

It is a cyclic number.

It is not a de Polignac number, because 79230821 - 2¹⁰ = 79229797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79230881) 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, 63590 + ... + 64823.

It is an arithmetic number, because the mean of its divisors is an integer number (19839963).

Almost surely, 2^79230821 is an apocalyptic number.

It is an amenable number.

79230821 is a deficient number, since it is larger than the sum of its proper divisors (129031).

79230821 is a wasteful number, since it uses less digits than its factorization.

79230821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129030.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 79230821 is about 8901.1696422437. The cubic root of 79230821 is about 429.5015334396.

It can be divided in two parts, 792 and 30821, that added together give a palindrome (31613).

The spelling of 79230821 in words is "seventy-nine million, two hundred thirty thousand, eight hundred twenty-one".