663940 has 24 divisors (see below), whose sum is σ = 1413720. Its totient is φ = 261888.

The previous prime is 663937. The next prime is 663959. The reversal of 663940 is 49366.

It can be written as a sum of positive squares in 4 ways, for example, as 20736 + 643204 = 144^2 + 802^2 .

It is a junction number, because it is equal to n+sod(n) for n = 663899 and 663908.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1594 + ... + 1966.

It is an arithmetic number, because the mean of its divisors is an integer number (58905).

2⁶⁶³⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

663940 is an abundant number, since it is smaller than the sum of its proper divisors (749780).

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

663940 is a wasteful number, since it uses less digits than its factorization.

663940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 663940 is about 814.8251346148. The cubic root of 663940 is about 87.2387855965.

The spelling of 663940 in words is "six hundred sixty-three thousand, nine hundred forty".