15721225617 has 8 divisors (see below), whose sum is σ = 20963672320. Its totient is φ = 10479798000.

The previous prime is 15721225603. The next prime is 15721225633. The reversal of 15721225617 is 71652212751.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15721225617 - 2¹² = 15721221521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15721225687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218017 + ... + 281022.

It is an arithmetic number, because the mean of its divisors is an integer number (2620459040).

Almost surely, 2^15721225617 is an apocalyptic number.

It is an amenable number.

15721225617 is a deficient number, since it is larger than the sum of its proper divisors (5242446703).

15721225617 is a wasteful number, since it uses less digits than its factorization.

15721225617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509543.

The product of its digits is 58800, while the sum is 39.

The spelling of 15721225617 in words is "fifteen billion, seven hundred twenty-one million, two hundred twenty-five thousand, six hundred seventeen".