155638979 has 2 divisors, whose sum is σ = 155638980. Its totient is φ = 155638978.

The previous prime is 155638939. The next prime is 155638981. The reversal of 155638979 is 979836551.

155638979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155638979 - 2¹² = 155634883 is a prime.

Together with 155638981, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155638979.

It is not a weakly prime, because it can be changed into another prime (155638939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77819489 + 77819490.

It is an arithmetic number, because the mean of its divisors is an integer number (77819490).

Almost surely, 2^155638979 is an apocalyptic number.

155638979 is a deficient number, since it is larger than the sum of its proper divisors (1).

155638979 is an equidigital number, since it uses as much as digits as its factorization.

155638979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2041200, while the sum is 53.

The square root of 155638979 is about 12475.5352189796. The cubic root of 155638979 is about 537.9056727612.

It can be divided in two parts, 15563 and 8979, that added together give a palindrome (24542).

The spelling of 155638979 in words is "one hundred fifty-five million, six hundred thirty-eight thousand, nine hundred seventy-nine".