66956216761 has 16 divisors (see below), whose sum is σ = 76842639360. Its totient is φ = 57150313920.

The previous prime is 66956216741. The next prime is 66956216801. The reversal of 66956216761 is 16761265966.

It is not a de Polignac number, because 66956216761 - 2²⁷ = 66821999033 is a prime.

It is a super-2 number, since 2×66956216761² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66956216741) 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, 4581576 + ... + 4596166.

It is an arithmetic number, because the mean of its divisors is an integer number (4802664960).

Almost surely, 2^66956216761 is an apocalyptic number.

It is an amenable number.

66956216761 is a deficient number, since it is larger than the sum of its proper divisors (9886422599).

66956216761 is a wasteful number, since it uses less digits than its factorization.

66956216761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17304.

The product of its digits is 4898880, while the sum is 55.

The spelling of 66956216761 in words is "sixty-six billion, nine hundred fifty-six million, two hundred sixteen thousand, seven hundred sixty-one".