155657312421 has 16 divisors (see below), whose sum is σ = 223532386560. Its totient is φ = 95778636480.

The previous prime is 155657312407. The next prime is 155657312453. The reversal of 155657312421 is 124213756551.

It is not a de Polignac number, because 155657312421 - 2⁶ = 155657312357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155657312621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 150660 + ... + 577938.

It is an arithmetic number, because the mean of its divisors is an integer number (13970774160).

Almost surely, 2^155657312421 is an apocalyptic number.

It is an amenable number.

155657312421 is a deficient number, since it is larger than the sum of its proper divisors (67875074139).

155657312421 is a wasteful number, since it uses less digits than its factorization.

155657312421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436636.

The product of its digits is 252000, while the sum is 42.

The spelling of 155657312421 in words is "one hundred fifty-five billion, six hundred fifty-seven million, three hundred twelve thousand, four hundred twenty-one".