15721687609 has 8 divisors (see below), whose sum is σ = 15920043552. Its totient is φ = 15523544640.

The previous prime is 15721687589. The next prime is 15721687613. The reversal of 15721687609 is 90678612751.

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

It is a cyclic number.

It is not a de Polignac number, because 15721687609 - 2⁷ = 15721687481 is a prime.

It is a super-2 number, since 2×15721687609² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15721687679) 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, 98017 + ... + 202609.

It is an arithmetic number, because the mean of its divisors is an integer number (1990005444).

Almost surely, 2^15721687609 is an apocalyptic number.

It is an amenable number.

15721687609 is a deficient number, since it is larger than the sum of its proper divisors (198355943).

15721687609 is a wasteful number, since it uses less digits than its factorization.

15721687609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106487.

The product of its (nonzero) digits is 1270080, while the sum is 52.

The spelling of 15721687609 in words is "fifteen billion, seven hundred twenty-one million, six hundred eighty-seven thousand, six hundred nine".