79318021 has 2 divisors, whose sum is σ = 79318022. Its totient is φ = 79318020.

The previous prime is 79318009. The next prime is 79318033. The reversal of 79318021 is 12081397.

It is a balanced prime because it is at equal distance from previous prime (79318009) and next prime (79318033).

It can be written as a sum of positive squares in only one way, i.e., 68657796 + 10660225 = 8286^2 + 3265^2 .

It is a cyclic number.

It is not a de Polignac number, because 79318021 - 2⁹ = 79317509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79318061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39659010 + 39659011.

It is an arithmetic number, because the mean of its divisors is an integer number (39659011).

Almost surely, 2^79318021 is an apocalyptic number.

It is an amenable number.

79318021 is a deficient number, since it is larger than the sum of its proper divisors (1).

79318021 is an equidigital number, since it uses as much as digits as its factorization.

79318021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 79318021 is about 8906.0665279348. The cubic root of 79318021 is about 429.6590428607.

The spelling of 79318021 in words is "seventy-nine million, three hundred eighteen thousand, twenty-one".