13556381 has 2 divisors, whose sum is σ = 13556382. Its totient is φ = 13556380.

The previous prime is 13556377. The next prime is 13556383. The reversal of 13556381 is 18365531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13388281 + 168100 = 3659^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 13556381 - 2² = 13556377 is a prime.

It is a super-2 number, since 2×13556381² = 367550931634322, which contains 22 as substring.

Together with 13556383, 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 (13556383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6778190 + 6778191.

It is an arithmetic number, because the mean of its divisors is an integer number (6778191).

Almost surely, 2^13556381 is an apocalyptic number.

It is an amenable number.

13556381 is a deficient number, since it is larger than the sum of its proper divisors (1).

13556381 is an equidigital number, since it uses as much as digits as its factorization.

13556381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 32.

The square root of 13556381 is about 3681.8991023655. The cubic root of 13556381 is about 238.4411761396.

The spelling of 13556381 in words is "thirteen million, five hundred fifty-six thousand, three hundred eighty-one".