10917664947721 has 9 divisors (see below), whose sum is σ = 12700167763149. Its totient is φ = 9357978701484.

The previous prime is 10917664947713. The next prime is 10917664947757. The reversal of 10917664947721 is 12774946671901.

The square root of 10917664947721 is 3304189.

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

It is not a de Polignac number, because 10917664947721 - 2³ = 10917664947713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10917664947701) 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, 22893310 + ... + 23365336.

It is an arithmetic number, because the mean of its divisors is an integer number (1411129751461).

Almost surely, 2^{10917664947721} is an apocalyptic number.

10917664947721 is the 3304189-th square number.

10917664947721 is the 1652095-th centered octagonal number.

It is an amenable number.

10917664947721 is a deficient number, since it is larger than the sum of its proper divisors (1782502815428).

10917664947721 is an frugal number, since it uses more digits than its factorization.

10917664947721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944068 (or 472034 counting only the distinct ones).

The product of its (nonzero) digits is 32006016, while the sum is 64.

Multiplying 10917664947721 by its sum of digits (64), we get a square (698730556654144 = 26433512²).

The spelling of 10917664947721 in words is "ten trillion, nine hundred seventeen billion, six hundred sixty-four million, nine hundred forty-seven thousand, seven hundred twenty-one".