66457021824 has 96 divisors (see below), whose sum is σ = 191448145200. Its totient is φ = 22127883264.

The previous prime is 66457021823. The next prime is 66457021837. The reversal of 66457021824 is 42812075466.

66457021824 is a `hidden beast` number, since 6 + 64 + 570 + 2 + 18 + 2 + 4 = 666.

66457021824 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×66457021824² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66457021824.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66457021823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1027302 + ... + 1090074.

Almost surely, 2^66457021824 is an apocalyptic number.

66457021824 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66457021824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95724072600).

66457021824 is an abundant number, since it is smaller than the sum of its proper divisors (124991123376).

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

66457021824 is a wasteful number, since it uses less digits than its factorization.

66457021824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63712 (or 63697 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 66457021824 in words is "sixty-six billion, four hundred fifty-seven million, twenty-one thousand, eight hundred twenty-four".