665655520 has 24 divisors (see below), whose sum is σ = 1572611544. Its totient is φ = 266262144.

The previous prime is 665655517. The next prime is 665655527. The reversal of 665655520 is 25556566.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665655527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2080014 + ... + 2080333.

It is an arithmetic number, because the mean of its divisors is an integer number (65525481).

Almost surely, 2^665655520 is an apocalyptic number.

It is an amenable number.

665655520 is an abundant number, since it is smaller than the sum of its proper divisors (906956024).

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

665655520 is a wasteful number, since it uses less digits than its factorization.

665655520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4160362 (or 4160354 counting only the distinct ones).

The product of its (nonzero) digits is 270000, while the sum is 40.

The square root of 665655520 is about 25800.3007734406. The cubic root of 665655520 is about 873.1385822695.

The spelling of 665655520 in words is "six hundred sixty-five million, six hundred fifty-five thousand, five hundred twenty".