665570430625 has 15 divisors (see below), whose sum is σ = 831722297263. Its totient is φ = 532440028000.

The previous prime is 665570430619. The next prime is 665570430631. The reversal of 665570430625 is 526034075566.

The square root of 665570430625 is 815825.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (665570430619) and next prime (665570430631).

It can be written as a sum of positive squares in 7 ways, for example, as 387360598689 + 278209831936 = 622383^2 + 527456^2 .

It is not a de Polignac number, because 665570430625 - 2⁹ = 665570430113 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 20379309 + ... + 20411941.

Almost surely, 2^665570430625 is an apocalyptic number.

665570430625 is the 815825-th square number.

665570430625 is the 407913-rd centered octagonal number.

It is an amenable number.

665570430625 is a deficient number, since it is larger than the sum of its proper divisors (166151866638).

665570430625 is an frugal number, since it uses more digits than its factorization.

665570430625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65286 (or 32638 counting only the distinct ones).

The product of its (nonzero) digits is 4536000, while the sum is 49.

Multiplying 665570430625 by its sum of digits (49), we get a square (32612951100625 = 5710775²).

The spelling of 665570430625 in words is "six hundred sixty-five billion, five hundred seventy million, four hundred thirty thousand, six hundred twenty-five".