155085631 has 2 divisors, whose sum is σ = 155085632. Its totient is φ = 155085630.

The previous prime is 155085613. The next prime is 155085643. The reversal of 155085631 is 136580551.

Together with previous prime (155085613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (136580551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155085631 - 2¹¹ = 155083583 is a prime.

It is a super-2 number, since 2×155085631² = 48103105885336322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155085661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77542815 + 77542816.

It is an arithmetic number, because the mean of its divisors is an integer number (77542816).

Almost surely, 2^155085631 is an apocalyptic number.

155085631 is a deficient number, since it is larger than the sum of its proper divisors (1).

155085631 is an equidigital number, since it uses as much as digits as its factorization.

155085631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 34.

The square root of 155085631 is about 12453.3381468585. The cubic root of 155085631 is about 537.2674383133.

The spelling of 155085631 in words is "one hundred fifty-five million, eighty-five thousand, six hundred thirty-one".