663981266 has 16 divisors (see below), whose sum is σ = 1078792344. Its totient is φ = 304679424.

The previous prime is 663981251. The next prime is 663981271. The reversal of 663981266 is 662189366.

663981266 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 646634041 + 17347225 = 25429^2 + 4165^2 .

It is a super-2 number, since 2×663981266² = 881742243197925512, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 663981266.

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, 69311 + ... + 78306.

Almost surely, 2^663981266 is an apocalyptic number.

663981266 is a deficient number, since it is larger than the sum of its proper divisors (414811078).

663981266 is a wasteful number, since it uses less digits than its factorization.

663981266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147805.

The product of its digits is 559872, while the sum is 47.

The square root of 663981266 is about 25767.8339407875. The cubic root of 663981266 is about 872.4059294917.

The spelling of 663981266 in words is "six hundred sixty-three million, nine hundred eighty-one thousand, two hundred sixty-six".