663981271 has 2 divisors, whose sum is σ = 663981272. Its totient is φ = 663981270.

The previous prime is 663981251. The next prime is 663981289. The reversal of 663981271 is 172189366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663981271 - 2¹¹ = 663979223 is a prime.

It is a super-2 number, since 2×663981271² = 881742256477550882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663981251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331990635 + 331990636.

It is an arithmetic number, because the mean of its divisors is an integer number (331990636).

Almost surely, 2^663981271 is an apocalyptic number.

663981271 is a deficient number, since it is larger than the sum of its proper divisors (1).

663981271 is an equidigital number, since it uses as much as digits as its factorization.

663981271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 663981271 is about 25767.8340378077. The cubic root of 663981271 is about 872.4059316816.

The spelling of 663981271 in words is "six hundred sixty-three million, nine hundred eighty-one thousand, two hundred seventy-one".