66331872 has 120 divisors (see below), whose sum is σ = 197527176. Its totient is φ = 21835008.

The previous prime is 66331849. The next prime is 66331873. The reversal of 66331872 is 27813366.

It is a happy number.

66331872 is a `hidden beast` number, since 6 + 633 + 18 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66331873) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 406863 + ... + 407025.

Almost surely, 2^66331872 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 66331872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98763588).

66331872 is an abundant number, since it is smaller than the sum of its proper divisors (131195304).

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

66331872 is a wasteful number, since it uses less digits than its factorization.

66331872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 325 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 66331872 is about 8144.4381021652. The cubic root of 66331872 is about 404.8002306966.

The spelling of 66331872 in words is "sixty-six million, three hundred thirty-one thousand, eight hundred seventy-two".