66566221632 has 448 divisors, whose sum is σ = 217278996480. Its totient is φ = 19889971200.

The previous prime is 66566221583. The next prime is 66566221721. The reversal of 66566221632 is 23612266566.

66566221632 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 6 + 2 + 2 + 1 + 632 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 61013407 + ... + 61014497.

It is an arithmetic number, because the mean of its divisors is an integer number (484997760).

Almost surely, 2^66566221632 is an apocalyptic number.

66566221632 is a gapful number since it is divisible by the number (62) 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 66566221632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108639498240).

66566221632 is an abundant number, since it is smaller than the sum of its proper divisors (150712774848).

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

66566221632 is a wasteful number, since it uses less digits than its factorization.

66566221632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1227 (or 1211 counting only the distinct ones).

The product of its digits is 933120, while the sum is 45.

The spelling of 66566221632 in words is "sixty-six billion, five hundred sixty-six million, two hundred twenty-one thousand, six hundred thirty-two".