13787621 has 2 divisors, whose sum is σ = 13787622. Its totient is φ = 13787620.

The previous prime is 13787593. The next prime is 13787623. The reversal of 13787621 is 12678731.

13787621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9523396 + 4264225 = 3086^2 + 2065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13787621 is a prime.

Together with 13787623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13787623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6893810 + 6893811.

It is an arithmetic number, because the mean of its divisors is an integer number (6893811).

Almost surely, 2^13787621 is an apocalyptic number.

It is an amenable number.

13787621 is a deficient number, since it is larger than the sum of its proper divisors (1).

13787621 is an equidigital number, since it uses as much as digits as its factorization.

13787621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 35.

The square root of 13787621 is about 3713.1685929944. The cubic root of 13787621 is about 239.7892884364.

The spelling of 13787621 in words is "thirteen million, seven hundred eighty-seven thousand, six hundred twenty-one".