66657631523 has 6 divisors (see below), whose sum is σ = 77540510196. Its totient is φ = 57135112692.

The previous prime is 66657631471. The next prime is 66657631577. The reversal of 66657631523 is 32513675666.

It is not a de Polignac number, because 66657631523 - 2¹⁶ = 66657565987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66657631583) 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 5 ways as a sum of consecutive naturals, for example, 680179865 + ... + 680179962.

It is an arithmetic number, because the mean of its divisors is an integer number (12923418366).

Almost surely, 2^66657631523 is an apocalyptic number.

66657631523 is a deficient number, since it is larger than the sum of its proper divisors (10882878673).

66657631523 is a wasteful number, since it uses less digits than its factorization.

66657631523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360359841 (or 1360359834 counting only the distinct ones).

The product of its digits is 4082400, while the sum is 50.

The spelling of 66657631523 in words is "sixty-six billion, six hundred fifty-seven million, six hundred thirty-one thousand, five hundred twenty-three".