12915021 has 16 divisors (see below), whose sum is σ = 19764864. Its totient is φ = 7348224.

The previous prime is 12915013. The next prime is 12915031. The reversal of 12915021 is 12051921.

It is not a de Polignac number, because 12915021 - 2³ = 12915013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12915031) 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, 4201 + ... + 6593.

It is an arithmetic number, because the mean of its divisors is an integer number (1235304).

Almost surely, 2^12915021 is an apocalyptic number.

It is an amenable number.

12915021 is a deficient number, since it is larger than the sum of its proper divisors (6849843).

12915021 is a wasteful number, since it uses less digits than its factorization.

12915021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 12915021 is about 3593.7474869556. The cubic root of 12915021 is about 234.6200045590.

Adding to 12915021 its reverse (12051921), we get a palindrome (24966942).

The spelling of 12915021 in words is "twelve million, nine hundred fifteen thousand, twenty-one".