155978279 has 2 divisors, whose sum is σ = 155978280. Its totient is φ = 155978278.

The previous prime is 155978261. The next prime is 155978299. The reversal of 155978279 is 972879551.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155978279 - 2²⁰ = 154929703 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155978279.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155978209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77989139 + 77989140.

It is an arithmetic number, because the mean of its divisors is an integer number (77989140).

Almost surely, 2^155978279 is an apocalyptic number.

155978279 is a deficient number, since it is larger than the sum of its proper divisors (1).

155978279 is an equidigital number, since it uses as much as digits as its factorization.

155978279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1587600, while the sum is 53.

The square root of 155978279 is about 12489.1264306196. The cubic root of 155978279 is about 538.2962752710.

The spelling of 155978279 in words is "one hundred fifty-five million, nine hundred seventy-eight thousand, two hundred seventy-nine".