79921559 has 2 divisors, whose sum is σ = 79921560. Its totient is φ = 79921558.

The previous prime is 79921507. The next prime is 79921561. The reversal of 79921559 is 95512997.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79921559 is a prime.

Together with 79921561, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79921579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39960779 + 39960780.

It is an arithmetic number, because the mean of its divisors is an integer number (39960780).

Almost surely, 2^79921559 is an apocalyptic number.

79921559 is a deficient number, since it is larger than the sum of its proper divisors (1).

79921559 is an equidigital number, since it uses as much as digits as its factorization.

79921559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 255150, while the sum is 47.

The square root of 79921559 is about 8939.8858493831. The cubic root of 79921559 is about 430.7460619432.

The spelling of 79921559 in words is "seventy-nine million, nine hundred twenty-one thousand, five hundred fifty-nine".