66260422921 has 27 divisors (see below), whose sum is σ = 84747945933. Its totient is φ = 51616053720.

The previous prime is 66260422913. The next prime is 66260422933. The reversal of 66260422921 is 12922406266.

The square root of 66260422921 is 257411.

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

It is not a de Polignac number, because 66260422921 - 2³ = 66260422913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66260422981) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 19818976 + ... + 19822318.

Almost surely, 2^66260422921 is an apocalyptic number.

66260422921 is the 257411-st square number.

66260422921 is the 128706-th centered octagonal number.

It is an amenable number.

66260422921 is a deficient number, since it is larger than the sum of its proper divisors (18487523012).

66260422921 is an frugal number, since it uses more digits than its factorization.

66260422921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6722 (or 3361 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 40.

The spelling of 66260422921 in words is "sixty-six billion, two hundred sixty million, four hundred twenty-two thousand, nine hundred twenty-one".