155689631 has 2 divisors, whose sum is σ = 155689632. Its totient is φ = 155689630.

The previous prime is 155689577. The next prime is 155689637. The reversal of 155689631 is 136986551.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155689631 is a prime.

It is a super-2 number, since 2×155689631² = 48478522401832322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155689637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77844815 + 77844816.

It is an arithmetic number, because the mean of its divisors is an integer number (77844816).

Almost surely, 2^155689631 is an apocalyptic number.

155689631 is a deficient number, since it is larger than the sum of its proper divisors (1).

155689631 is an equidigital number, since it uses as much as digits as its factorization.

155689631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 44.

The square root of 155689631 is about 12477.5651070231. The cubic root of 155689631 is about 537.9640194195.

The spelling of 155689631 in words is "one hundred fifty-five million, six hundred eighty-nine thousand, six hundred thirty-one".