663720060521251 has 2 divisors, whose sum is σ = 663720060521252. Its totient is φ = 663720060521250.

The previous prime is 663720060521191. The next prime is 663720060521269. The reversal of 663720060521251 is 152125060027366.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663720060521251 - 2⁹ = 663720060520739 is a prime.

It is not a weakly prime, because it can be changed into another prime (663720060531251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331860030260625 + 331860030260626.

It is an arithmetic number, because the mean of its divisors is an integer number (331860030260626).

Almost surely, 2^{663720060521251} is an apocalyptic number.

663720060521251 is a deficient number, since it is larger than the sum of its proper divisors (1).

663720060521251 is an equidigital number, since it uses as much as digits as its factorization.

663720060521251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 663720060521251 in words is "six hundred sixty-three trillion, seven hundred twenty billion, sixty million, five hundred twenty-one thousand, two hundred fifty-one".