666717804 has 60 divisors (see below), whose sum is σ = 1769003544. Its totient is φ = 218915136.

The previous prime is 666717797. The next prime is 666717811. The reversal of 666717804 is 408717666.

It is an interprime number because it is at equal distance from previous prime (666717797) and next prime (666717811).

It is a self number, because there is not a number n which added to its sum of digits gives 666717804.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6352 + ... + 37064.

Almost surely, 2^666717804 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 666717804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (884501772).

666717804 is an abundant number, since it is smaller than the sum of its proper divisors (1102285740).

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

666717804 is a wasteful number, since it uses less digits than its factorization.

666717804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30796 (or 30785 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 666717804 is about 25820.8792259288. The cubic root of 666717804 is about 873.6028004529.

The spelling of 666717804 in words is "six hundred sixty-six million, seven hundred seventeen thousand, eight hundred four".