663811481 has 2 divisors, whose sum is σ = 663811482. Its totient is φ = 663811480.

The previous prime is 663811471. The next prime is 663811513. The reversal of 663811481 is 184118366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 494395225 + 169416256 = 22235^2 + 13016^2 .

It is a cyclic number.

It is not a de Polignac number, because 663811481 - 2¹⁰ = 663810457 is a prime.

It is a super-3 number, since 3×663811481³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (663811471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331905740 + 331905741.

It is an arithmetic number, because the mean of its divisors is an integer number (331905741).

Almost surely, 2^663811481 is an apocalyptic number.

It is an amenable number.

663811481 is a deficient number, since it is larger than the sum of its proper divisors (1).

663811481 is an equidigital number, since it uses as much as digits as its factorization.

663811481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 38.

The square root of 663811481 is about 25764.5392157516. The cubic root of 663811481 is about 872.3315629017.

The spelling of 663811481 in words is "six hundred sixty-three million, eight hundred eleven thousand, four hundred eighty-one".