155123931 has 4 divisors (see below), whose sum is σ = 206831912. Its totient is φ = 103415952.

The previous prime is 155123911. The next prime is 155123933. The reversal of 155123931 is 139321551.

155123931 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 an emirpimes, since its reverse is a distinct semiprime: 139321551 = 3 ⋅46440517.

It is not a de Polignac number, because 155123931 - 2¹³ = 155115739 is a prime.

It is a super-2 number, since 2×155123931² = 48126867937785522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155123933) 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, 25853986 + ... + 25853991.

It is an arithmetic number, because the mean of its divisors is an integer number (51707978).

Almost surely, 2^155123931 is an apocalyptic number.

155123931 is a deficient number, since it is larger than the sum of its proper divisors (51707981).

155123931 is an equidigital number, since it uses as much as digits as its factorization.

155123931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51707980.

The product of its digits is 4050, while the sum is 30.

The square root of 155123931 is about 12454.8757922349. The cubic root of 155123931 is about 537.3116625892.

The spelling of 155123931 in words is "one hundred fifty-five million, one hundred twenty-three thousand, nine hundred thirty-one".