155907681 has 4 divisors (see below), whose sum is σ = 207876912. Its totient is φ = 103938452.

The previous prime is 155907671. The next prime is 155907709. The reversal of 155907681 is 186709551.

155907681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155907681 - 2¹⁷ = 155776609 is a prime.

It is a super-2 number, since 2×155907681² = 48614409989595522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155907671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25984611 + ... + 25984616.

It is an arithmetic number, because the mean of its divisors is an integer number (51969228).

Almost surely, 2^155907681 is an apocalyptic number.

It is an amenable number.

155907681 is a deficient number, since it is larger than the sum of its proper divisors (51969231).

155907681 is an equidigital number, since it uses as much as digits as its factorization.

155907681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51969230.

The product of its (nonzero) digits is 75600, while the sum is 42.

The square root of 155907681 is about 12486.2997321064. The cubic root of 155907681 is about 538.2150494840.

The spelling of 155907681 in words is "one hundred fifty-five million, nine hundred seven thousand, six hundred eighty-one".