79752821 has 2 divisors, whose sum is σ = 79752822. Its totient is φ = 79752820.

The previous prime is 79752817. The next prime is 79752857. The reversal of 79752821 is 12825797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79744900 + 7921 = 8930^2 + 89^2 .

It is a cyclic number.

It is not a de Polignac number, because 79752821 - 2² = 79752817 is a prime.

It is equal to p_4655858 and since 79752821 and 4655858 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79752521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39876410 + 39876411.

It is an arithmetic number, because the mean of its divisors is an integer number (39876411).

Almost surely, 2^79752821 is an apocalyptic number.

It is an amenable number.

79752821 is a deficient number, since it is larger than the sum of its proper divisors (1).

79752821 is an equidigital number, since it uses as much as digits as its factorization.

79752821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 41.

The square root of 79752821 is about 8930.4434940265. The cubic root of 79752821 is about 430.4427043264.

The spelling of 79752821 in words is "seventy-nine million, seven hundred fifty-two thousand, eight hundred twenty-one".