13630781 has 2 divisors, whose sum is σ = 13630782. Its totient is φ = 13630780.

The previous prime is 13630769. The next prime is 13630801. The reversal of 13630781 is 18703631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9765625 + 3865156 = 3125^2 + 1966^2 .

It is a cyclic number.

It is not a de Polignac number, because 13630781 - 2²² = 9436477 is a prime.

It is a super-2 number, since 2×13630781² = 371596381339922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13630741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6815390 + 6815391.

It is an arithmetic number, because the mean of its divisors is an integer number (6815391).

Almost surely, 2^13630781 is an apocalyptic number.

It is an amenable number.

13630781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13630781 is an equidigital number, since it uses as much as digits as its factorization.

13630781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 13630781 is about 3691.9887594628. The cubic root of 13630781 is about 238.8765840987.

The spelling of 13630781 in words is "thirteen million, six hundred thirty thousand, seven hundred eighty-one".