13871621 has 2 divisors, whose sum is σ = 13871622. Its totient is φ = 13871620.

The previous prime is 13871617. The next prime is 13871623. The reversal of 13871621 is 12617831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11826721 + 2044900 = 3439^2 + 1430^2 .

It is a cyclic number.

It is not a de Polignac number, because 13871621 - 2² = 13871617 is a prime.

Together with 13871623, 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 (13871623) 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, 6935810 + 6935811.

It is an arithmetic number, because the mean of its divisors is an integer number (6935811).

Almost surely, 2^13871621 is an apocalyptic number.

It is an amenable number.

13871621 is a deficient number, since it is larger than the sum of its proper divisors (1).

13871621 is an equidigital number, since it uses as much as digits as its factorization.

13871621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 29.

The square root of 13871621 is about 3724.4625115579. The cubic root of 13871621 is about 240.2752686499.

The spelling of 13871621 in words is "thirteen million, eight hundred seventy-one thousand, six hundred twenty-one".