15721275112721 has 4 divisors (see below), whose sum is σ = 15721339014000. Its totient is φ = 15721211211444.

The previous prime is 15721275112687. The next prime is 15721275112783. The reversal of 15721275112721 is 12721157212751.

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 15721275112721 - 2¹⁰ = 15721275111697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15721275112021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31580171 + ... + 32074128.

It is an arithmetic number, because the mean of its divisors is an integer number (3930334753500).

Almost surely, 2^{15721275112721} is an apocalyptic number.

It is an amenable number.

15721275112721 is a deficient number, since it is larger than the sum of its proper divisors (63901279).

15721275112721 is an equidigital number, since it uses as much as digits as its factorization.

15721275112721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63901278.

The product of its digits is 137200, while the sum is 44.

The spelling of 15721275112721 in words is "fifteen trillion, seven hundred twenty-one billion, two hundred seventy-five million, one hundred twelve thousand, seven hundred twenty-one".