13961921 has 2 divisors, whose sum is σ = 13961922. Its totient is φ = 13961920.

The previous prime is 13961917. The next prime is 13961923. The reversal of 13961921 is 12916931.

13961921 is digitally balanced in base 3, 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., 13957696 + 4225 = 3736^2 + 65^2 .

It is an emirp because it is prime and its reverse (12916931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13961921 - 2² = 13961917 is a prime.

Together with 13961923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13961923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6980960 + 6980961.

It is an arithmetic number, because the mean of its divisors is an integer number (6980961).

Almost surely, 2^13961921 is an apocalyptic number.

It is an amenable number.

13961921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13961921 is an equidigital number, since it uses as much as digits as its factorization.

13961921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 32.

The square root of 13961921 is about 3736.5654015419. The cubic root of 13961921 is about 240.7955141768.

The spelling of 13961921 in words is "thirteen million, nine hundred sixty-one thousand, nine hundred twenty-one".