13151921 has 2 divisors, whose sum is σ = 13151922. Its totient is φ = 13151920.

The previous prime is 13151911. The next prime is 13151923. The reversal of 13151921 is 12915131.

13151921 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., 9541921 + 3610000 = 3089^2 + 1900^2 .

It is an emirp because it is prime and its reverse (12915131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13151921 - 2¹⁸ = 12889777 is a prime.

It is a Sophie Germain prime.

Together with 13151923, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (13151923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6575960 + 6575961.

It is an arithmetic number, because the mean of its divisors is an integer number (6575961).

Almost surely, 2^13151921 is an apocalyptic number.

It is an amenable number.

13151921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13151921 is an equidigital number, since it uses as much as digits as its factorization.

13151921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 270, while the sum is 23.

The square root of 13151921 is about 3626.5577342709. The cubic root of 13151921 is about 236.0458651163.

The spelling of 13151921 in words is "thirteen million, one hundred fifty-one thousand, nine hundred twenty-one".