66917992689 has 36 divisors (see below), whose sum is σ = 103775831796. Its totient is φ = 41518927296.

The previous prime is 66917992657. The next prime is 66917992699. The reversal of 66917992689 is 98629971966.

It can be written as a sum of positive squares in 2 ways, for example, as 52635830625 + 14282162064 = 229425^2 + 119508^2 .

It is not a de Polignac number, because 66917992689 - 2⁵ = 66917992657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66917992699) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13782 + ... + 366095.

Almost surely, 2^66917992689 is an apocalyptic number.

66917992689 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

66917992689 is a deficient number, since it is larger than the sum of its proper divisors (36857839107).

66917992689 is a wasteful number, since it uses less digits than its factorization.

66917992689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379966 (or 379940 counting only the distinct ones).

The product of its digits is 158723712, while the sum is 72.

The spelling of 66917992689 in words is "sixty-six billion, nine hundred seventeen million, nine hundred ninety-two thousand, six hundred eighty-nine".