13940639 has 2 divisors, whose sum is σ = 13940640. Its totient is φ = 13940638.

The previous prime is 13940617. The next prime is 13940651. The reversal of 13940639 is 93604931.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 13940639 - 2⁸ = 13940383 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 13940599 and 13940608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13940239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6970319 + 6970320.

It is an arithmetic number, because the mean of its divisors is an integer number (6970320).

Almost surely, 2^13940639 is an apocalyptic number.

13940639 is a deficient number, since it is larger than the sum of its proper divisors (1).

13940639 is an equidigital number, since it uses as much as digits as its factorization.

13940639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 13940639 is about 3733.7165130738. The cubic root of 13940639 is about 240.6731046570.

The spelling of 13940639 in words is "thirteen million, nine hundred forty thousand, six hundred thirty-nine".