315123021 has 32 divisors (see below), whose sum is σ = 476275200. Its totient is φ = 205882560.

The previous prime is 315123013. The next prime is 315123073. The reversal of 315123021 is 120321513.

It is not a de Polignac number, because 315123021 - 2³ = 315123013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 315122985 and 315123003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315123121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 334411 + ... + 335351.

It is an arithmetic number, because the mean of its divisors is an integer number (14883600).

Almost surely, 2^315123021 is an apocalyptic number.

It is an amenable number.

315123021 is a deficient number, since it is larger than the sum of its proper divisors (161152179).

315123021 is a wasteful number, since it uses less digits than its factorization.

315123021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1186 (or 1180 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 315123021 is about 17751.7047350388. The cubic root of 315123021 is about 680.4977763861.

Adding to 315123021 its reverse (120321513), we get a palindrome (435444534).

The spelling of 315123021 in words is "three hundred fifteen million, one hundred twenty-three thousand, twenty-one".