665990424 has 160 divisors (see below), whose sum is σ = 2048801040. Its totient is φ = 200448000.

The previous prime is 665990411. The next prime is 665990447. The reversal of 665990424 is 424099566.

It is a self number, because there is not a number n which added to its sum of digits gives 665990424.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1660624 + ... + 1661024.

Almost surely, 2^665990424 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 665990424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1024400520).

665990424 is an abundant number, since it is smaller than the sum of its proper divisors (1382810616).

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

665990424 is a wasteful number, since it uses less digits than its factorization.

665990424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 665990424 is about 25806.7902692295. The cubic root of 665990424 is about 873.2849886155.

The spelling of 665990424 in words is "six hundred sixty-five million, nine hundred ninety thousand, four hundred twenty-four".