66321996 has 48 divisors (see below), whose sum is σ = 170548224. Its totient is φ = 19930176.

The previous prime is 66321979. The next prime is 66322007. The reversal of 66321996 is 69912366.

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, 1765 + ... + 11651.

It is an arithmetic number, because the mean of its divisors is an integer number (3553088).

Almost surely, 2^66321996 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 66321996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85274112).

66321996 is an abundant number, since it is smaller than the sum of its proper divisors (104226228).

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

66321996 is a wasteful number, since it uses less digits than its factorization.

66321996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9950 (or 9948 counting only the distinct ones).

The product of its digits is 104976, while the sum is 42.

The square root of 66321996 is about 8143.8317762586. The cubic root of 66321996 is about 404.7801397741.

The spelling of 66321996 in words is "sixty-six million, three hundred twenty-one thousand, nine hundred ninety-six".