663906920 has 32 divisors (see below), whose sum is σ = 1518284520. Its totient is φ = 261208320.

The previous prime is 663906917. The next prime is 663906923. The reversal of 663906920 is 29609366.

It is an interprime number because it is at equal distance from previous prime (663906917) and next prime (663906923).

It can be written as a sum of positive squares in 4 ways, for example, as 235499716 + 428407204 = 15346^2 + 20698^2 .

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (663906923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133607 + ... + 138486.

Almost surely, 2^663906920 is an apocalyptic number.

It is an amenable number.

663906920 is an abundant number, since it is smaller than the sum of its proper divisors (854377600).

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

663906920 is a wasteful number, since it uses less digits than its factorization.

663906920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272165 (or 272161 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 41.

The square root of 663906920 is about 25766.3912878773. The cubic root of 663906920 is about 872.3733671713.

The spelling of 663906920 in words is "six hundred sixty-three million, nine hundred six thousand, nine hundred twenty".