663981251 has 2 divisors, whose sum is σ = 663981252. Its totient is φ = 663981250.

The previous prime is 663981233. The next prime is 663981271. The reversal of 663981251 is 152189366.

663981251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663981251 is a prime.

It is a super-2 number, since 2×663981251² = 881742203359050002, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 663981199 and 663981208.

It is not a weakly prime, because it can be changed into another prime (663981271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331990625 + 331990626.

It is an arithmetic number, because the mean of its divisors is an integer number (331990626).

Almost surely, 2^663981251 is an apocalyptic number.

663981251 is a deficient number, since it is larger than the sum of its proper divisors (1).

663981251 is an equidigital number, since it uses as much as digits as its factorization.

663981251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 41.

The square root of 663981251 is about 25767.8336497269. The cubic root of 663981251 is about 872.4059229222.

The spelling of 663981251 in words is "six hundred sixty-three million, nine hundred eighty-one thousand, two hundred fifty-one".