155990586581 has 2 divisors, whose sum is σ = 155990586582. Its totient is φ = 155990586580.

The previous prime is 155990586551. The next prime is 155990586613. The reversal of 155990586581 is 185685099551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119142328900 + 36848257681 = 345170^2 + 191959^2 .

It is a cyclic number.

It is not a de Polignac number, because 155990586581 - 2⁶ = 155990586517 is a prime.

It is a super-2 number, since 2×155990586581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155990586551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77995293290 + 77995293291.

It is an arithmetic number, because the mean of its divisors is an integer number (77995293291).

Almost surely, 2^155990586581 is an apocalyptic number.

It is an amenable number.

155990586581 is a deficient number, since it is larger than the sum of its proper divisors (1).

155990586581 is an equidigital number, since it uses as much as digits as its factorization.

155990586581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440000, while the sum is 62.

The spelling of 155990586581 in words is "one hundred fifty-five billion, nine hundred ninety million, five hundred eighty-six thousand, five hundred eighty-one".