13638749 has 2 divisors, whose sum is σ = 13638750. Its totient is φ = 13638748.

The previous prime is 13638739. The next prime is 13638763. The reversal of 13638749 is 94783631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8265625 + 5373124 = 2875^2 + 2318^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13638749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13638739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6819374 + 6819375.

It is an arithmetic number, because the mean of its divisors is an integer number (6819375).

Almost surely, 2^13638749 is an apocalyptic number.

It is an amenable number.

13638749 is a deficient number, since it is larger than the sum of its proper divisors (1).

13638749 is an equidigital number, since it uses as much as digits as its factorization.

13638749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 41.

The square root of 13638749 is about 3693.0676950200. The cubic root of 13638749 is about 238.9231208761.

The spelling of 13638749 in words is "thirteen million, six hundred thirty-eight thousand, seven hundred forty-nine".