663639937 has 4 divisors (see below), whose sum is σ = 667476180. Its totient is φ = 659803696.

The previous prime is 663639883. The next prime is 663639959. The reversal of 663639937 is 739936366.

663639937 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 605209201 + 58430736 = 24601^2 + 7644^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663639937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663639967) 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, 1917862 + ... + 1918207.

It is an arithmetic number, because the mean of its divisors is an integer number (166869045).

Almost surely, 2^663639937 is an apocalyptic number.

It is an amenable number.

663639937 is a deficient number, since it is larger than the sum of its proper divisors (3836243).

663639937 is a wasteful number, since it uses less digits than its factorization.

663639937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3836242.

The product of its digits is 3306744, while the sum is 52.

The square root of 663639937 is about 25761.2099288834. The cubic root of 663639937 is about 872.2564129823.

The spelling of 663639937 in words is "six hundred sixty-three million, six hundred thirty-nine thousand, nine hundred thirty-seven".