12531213521 has 4 divisors (see below), whose sum is σ = 12655285044. Its totient is φ = 12407142000.

The previous prime is 12531213511. The next prime is 12531213529.

12531213521 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5197689025 + 7333524496 = 72095^2 + 85636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12531213521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12531213529) 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, 62035610 + ... + 62035811.

It is an arithmetic number, because the mean of its divisors is an integer number (3163821261).

Almost surely, 2^12531213521 is an apocalyptic number.

It is an amenable number.

12531213521 is a deficient number, since it is larger than the sum of its proper divisors (124071523).

12531213521 is a wasteful number, since it uses less digits than its factorization.

12531213521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124071522.

The product of its digits is 1800, while the sum is 26.

The spelling of 12531213521 in words is "twelve billion, five hundred thirty-one million, two hundred thirteen thousand, five hundred twenty-one".