9615959721 has 9 divisors (see below), whose sum is σ = 13890144541. Its totient is φ = 6410443692.

The previous prime is 9615959701. The next prime is 9615959767. The reversal of 9615959721 is 1279595169.

The square root of 9615959721 is 98061.

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

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 9615959721 - 2³³ = 1026025129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9615959701) 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 8 ways as a sum of consecutive naturals, for example, 277840 + ... + 310526.

Almost surely, 2^9615959721 is an apocalyptic number.

9615959721 is the 98061-st square number.

9615959721 is the 49031-st centered octagonal number.

It is an amenable number.

9615959721 is a deficient number, since it is larger than the sum of its proper divisors (4274184820).

9615959721 is an frugal number, since it uses more digits than its factorization.

9615959721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65380 (or 32690 counting only the distinct ones).

The product of its digits is 1530900, while the sum is 54.

The cubic root of 9615959721 is about 2126.4942456290.

The spelling of 9615959721 in words is "nine billion, six hundred fifteen million, nine hundred fifty-nine thousand, seven hundred twenty-one".