9712509721 has 16 divisors (see below), whose sum is σ = 10229587200. Its totient is φ = 9211496320.

The previous prime is 9712509707. The next prime is 9712509739. The reversal of 9712509721 is 1279052179.

It is a cyclic number.

It is not a de Polignac number, because 9712509721 - 2⁵ = 9712509689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9712509701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270210 + ... + 304036.

It is an arithmetic number, because the mean of its divisors is an integer number (639349200).

Almost surely, 2^9712509721 is an apocalyptic number.

It is an amenable number.

9712509721 is a deficient number, since it is larger than the sum of its proper divisors (517077479).

9712509721 is a wasteful number, since it uses less digits than its factorization.

9712509721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34064.

The product of its (nonzero) digits is 79380, while the sum is 43.

The square root of 9712509721 is about 98552.0660412556. The cubic root of 9712509721 is about 2133.5876499847.

The spelling of 9712509721 in words is "nine billion, seven hundred twelve million, five hundred nine thousand, seven hundred twenty-one".