66657397599 has 36 divisors (see below), whose sum is σ = 104310680760. Its totient is φ = 40999608000.

The previous prime is 66657397589. The next prime is 66657397627. The reversal of 66657397599 is 99579375666.

It is not a de Polignac number, because 66657397599 - 2⁵ = 66657397567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66657397519) 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, 3414037 + ... + 3433505.

It is an arithmetic number, because the mean of its divisors is an integer number (2897518910).

Almost surely, 2^66657397599 is an apocalyptic number.

66657397599 is a deficient number, since it is larger than the sum of its proper divisors (37653283161).

66657397599 is a wasteful number, since it uses less digits than its factorization.

66657397599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21752 (or 21736 counting only the distinct ones).

The product of its digits is 578680200, while the sum is 72.

The spelling of 66657397599 in words is "sixty-six billion, six hundred fifty-seven million, three hundred ninety-seven thousand, five hundred ninety-nine".