12531156421 has 16 divisors (see below), whose sum is σ = 14631890944. Its totient is φ = 10510383744.

The previous prime is 12531156413. The next prime is 12531156427. The reversal of 12531156421 is 12465113521.

It is not a de Polignac number, because 12531156421 - 2³ = 12531156413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12531156427) 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, 31650 + ... + 161443.

It is an arithmetic number, because the mean of its divisors is an integer number (914493184).

Almost surely, 2^12531156421 is an apocalyptic number.

It is an amenable number.

12531156421 is a deficient number, since it is larger than the sum of its proper divisors (2100734523).

12531156421 is a wasteful number, since it uses less digits than its factorization.

12531156421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193300.

The product of its digits is 7200, while the sum is 31.

Adding to 12531156421 its reverse (12465113521), we get a palindrome (24996269942).

The spelling of 12531156421 in words is "twelve billion, five hundred thirty-one million, one hundred fifty-six thousand, four hundred twenty-one".