12581522521 has 4 divisors (see below), whose sum is σ = 12874116112. Its totient is φ = 12288928932.

The previous prime is 12581522507. The next prime is 12581522549. The reversal of 12581522521 is 12522518521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12581522521 - 2⁵ = 12581522489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12581522021) 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, 146296731 + ... + 146296816.

It is an arithmetic number, because the mean of its divisors is an integer number (3218529028).

Almost surely, 2^12581522521 is an apocalyptic number.

It is an amenable number.

12581522521 is a deficient number, since it is larger than the sum of its proper divisors (292593591).

12581522521 is an equidigital number, since it uses as much as digits as its factorization.

12581522521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292593590.

The product of its digits is 16000, while the sum is 34.

The spelling of 12581522521 in words is "twelve billion, five hundred eighty-one million, five hundred twenty-two thousand, five hundred twenty-one".