665356428 has 72 divisors (see below), whose sum is σ = 1843697856. Its totient is φ = 200642400.

The previous prime is 665356427. The next prime is 665356451. The reversal of 665356428 is 824653566.

665356428 is a `hidden beast` number, since 6 + 65 + 3 + 564 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (665356427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79575 + ... + 87537.

Almost surely, 2^665356428 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 665356428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (921848928).

665356428 is an abundant number, since it is smaller than the sum of its proper divisors (1178341428).

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

665356428 is a wasteful number, since it uses less digits than its factorization.

665356428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8195 (or 8190 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 665356428 is about 25794.5038331812. The cubic root of 665356428 is about 873.0077899503.

The spelling of 665356428 in words is "six hundred sixty-five million, three hundred fifty-six thousand, four hundred twenty-eight".