66899552784 has 80 divisors (see below), whose sum is σ = 180632045952. Its totient is φ = 21295504384.

The previous prime is 66899552771. The next prime is 66899552791. The reversal of 66899552784 is 48725599866.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 632062 + ... + 730274.

Almost surely, 2^66899552784 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66899552784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90316022976).

66899552784 is an abundant number, since it is smaller than the sum of its proper divisors (113732493168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66899552784 is a wasteful number, since it uses less digits than its factorization.

66899552784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98864 (or 98858 counting only the distinct ones).

The product of its digits is 261273600, while the sum is 69.

The spelling of 66899552784 in words is "sixty-six billion, eight hundred ninety-nine million, five hundred fifty-two thousand, seven hundred eighty-four".