79899557 has 2 divisors, whose sum is σ = 79899558. Its totient is φ = 79899556.

The previous prime is 79899551. The next prime is 79899559. The reversal of 79899557 is 75599897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75238276 + 4661281 = 8674^2 + 2159^2 .

It is a cyclic number.

It is not a de Polignac number, because 79899557 - 2⁸ = 79899301 is a prime.

Together with 79899559, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 79899496 and 79899505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79899551) 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 as a sum of consecutive naturals, namely, 39949778 + 39949779.

It is an arithmetic number, because the mean of its divisors is an integer number (39949779).

Almost surely, 2^79899557 is an apocalyptic number.

It is an amenable number.

79899557 is a deficient number, since it is larger than the sum of its proper divisors (1).

79899557 is an equidigital number, since it uses as much as digits as its factorization.

79899557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7144200, while the sum is 59.

The square root of 79899557 is about 8938.6552120551. The cubic root of 79899557 is about 430.7065309130.

The spelling of 79899557 in words is "seventy-nine million, eight hundred ninety-nine thousand, five hundred fifty-seven".