665025440 has 24 divisors (see below), whose sum is σ = 1571122980. Its totient is φ = 266010112.

The previous prime is 665025421. The next prime is 665025461. The reversal of 665025440 is 44520566.

It can be written as a sum of positive squares in 2 ways, for example, as 653109136 + 11916304 = 25556^2 + 3452^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 665025397 and 665025406.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2078045 + ... + 2078364.

Almost surely, 2^665025440 is an apocalyptic number.

It is an amenable number.

665025440 is an abundant number, since it is smaller than the sum of its proper divisors (906097540).

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

665025440 is a wasteful number, since it uses less digits than its factorization.

665025440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4156424 (or 4156416 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 665025440 is about 25788.0871721809. The cubic root of 665025440 is about 872.8630038788.

The spelling of 665025440 in words is "six hundred sixty-five million, twenty-five thousand, four hundred forty".