12562516721 has 4 divisors (see below), whose sum is σ = 12721536000. Its totient is φ = 12403497444.

The previous prime is 12562516667. The next prime is 12562516739. The reversal of 12562516721 is 12761526521.

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 a de Polignac number, because none of the positive numbers 2^k-12562516721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12562516751) 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, 79509521 + ... + 79509678.

It is an arithmetic number, because the mean of its divisors is an integer number (3180384000).

Almost surely, 2^12562516721 is an apocalyptic number.

It is an amenable number.

12562516721 is a deficient number, since it is larger than the sum of its proper divisors (159019279).

12562516721 is an equidigital number, since it uses as much as digits as its factorization.

12562516721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159019278.

The product of its digits is 50400, while the sum is 38.

The spelling of 12562516721 in words is "twelve billion, five hundred sixty-two million, five hundred sixteen thousand, seven hundred twenty-one".