156639979 has 2 divisors, whose sum is σ = 156639980. Its totient is φ = 156639978.

The previous prime is 156639943. The next prime is 156639997. The reversal of 156639979 is 979936651.

156639979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with next prime (156639997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-156639979 is a prime.

It is a super-2 number, since 2×156639979² = 49072166042240882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (156639079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78319989 + 78319990.

It is an arithmetic number, because the mean of its divisors is an integer number (78319990).

Almost surely, 2^156639979 is an apocalyptic number.

156639979 is a deficient number, since it is larger than the sum of its proper divisors (1).

156639979 is an equidigital number, since it uses as much as digits as its factorization.

156639979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2755620, while the sum is 55.

The square root of 156639979 is about 12515.5894387759. The cubic root of 156639979 is about 539.0563985122.

The spelling of 156639979 in words is "one hundred fifty-six million, six hundred thirty-nine thousand, nine hundred seventy-nine".