663976081 has 4 divisors (see below), whose sum is σ = 664027632. Its totient is φ = 663924532.

The previous prime is 663976057. The next prime is 663976087. The reversal of 663976081 is 180679366.

663976081 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 663976081 - 2¹⁹ = 663451793 is a prime.

It is a super-2 number, since 2×663976081² = 881728472280237122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663976087) 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, 11970 + ... + 38356.

It is an arithmetic number, because the mean of its divisors is an integer number (166006908).

Almost surely, 2^663976081 is an apocalyptic number.

It is an amenable number.

663976081 is a deficient number, since it is larger than the sum of its proper divisors (51551).

663976081 is a wasteful number, since it uses less digits than its factorization.

663976081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51550.

The product of its (nonzero) digits is 326592, while the sum is 46.

The square root of 663976081 is about 25767.7333306599. The cubic root of 663976081 is about 872.4036586262.

The spelling of 663976081 in words is "six hundred sixty-three million, nine hundred seventy-six thousand, eighty-one".