155970391 has 2 divisors, whose sum is σ = 155970392. Its totient is φ = 155970390.

The previous prime is 155970379. The next prime is 155970401. The reversal of 155970391 is 193079551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155970391 - 2⁷ = 155970263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155970301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77985195 + 77985196.

It is an arithmetic number, because the mean of its divisors is an integer number (77985196).

Almost surely, 2^155970391 is an apocalyptic number.

155970391 is a deficient number, since it is larger than the sum of its proper divisors (1).

155970391 is an equidigital number, since it uses as much as digits as its factorization.

155970391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42525, while the sum is 40.

The square root of 155970391 is about 12488.8106319217. The cubic root of 155970391 is about 538.2872010319.

The spelling of 155970391 in words is "one hundred fifty-five million, nine hundred seventy thousand, three hundred ninety-one".