15672285721 has 9 divisors (see below), whose sum is σ = 16386326229. Its totient is φ = 14988127836.

The previous prime is 15672285709. The next prime is 15672285743. The reversal of 15672285721 is 12758227651.

It is a happy number.

The square root of 15672285721 is 125189.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 15672285721 - 2⁷ = 15672285593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15672285781) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2876626 + ... + 2882068.

Almost surely, 2^15672285721 is an apocalyptic number.

15672285721 is the 125189-th square number.

15672285721 is the 62595-th centered octagonal number.

It is an amenable number.

15672285721 is a deficient number, since it is larger than the sum of its proper divisors (714040508).

15672285721 is an frugal number, since it uses more digits than its factorization.

15672285721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10932 (or 5466 counting only the distinct ones).

The product of its digits is 470400, while the sum is 46.

The spelling of 15672285721 in words is "fifteen billion, six hundred seventy-two million, two hundred eighty-five thousand, seven hundred twenty-one".