665221392 has 120 divisors (see below), whose sum is σ = 2080679328. Its totient is φ = 196646400.

The previous prime is 665221327. The next prime is 665221411. The reversal of 665221392 is 293122566.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59823 + ... + 70065.

Almost surely, 2^665221392 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 665221392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1040339664).

665221392 is an abundant number, since it is smaller than the sum of its proper divisors (1415457936).

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

665221392 is a wasteful number, since it uses less digits than its factorization.

665221392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10309 (or 10300 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 665221392 is about 25791.8861660019. The cubic root of 665221392 is about 872.9487261407.

The spelling of 665221392 in words is "six hundred sixty-five million, two hundred twenty-one thousand, three hundred ninety-two".