13421057921 has 2 divisors, whose sum is σ = 13421057922. Its totient is φ = 13421057920.

The previous prime is 13421057891. The next prime is 13421057933. The reversal of 13421057921 is 12975012431.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13291553521 + 129504400 = 115289^2 + 11380^2 .

It is an emirp because it is prime and its reverse (12975012431) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13421057921 - 2⁶ = 13421057857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (13421057941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6710528960 + 6710528961.

It is an arithmetic number, because the mean of its divisors is an integer number (6710528961).

Almost surely, 2^13421057921 is an apocalyptic number.

It is an amenable number.

13421057921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13421057921 is an equidigital number, since it uses as much as digits as its factorization.

13421057921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The spelling of 13421057921 in words is "thirteen billion, four hundred twenty-one million, fifty-seven thousand, nine hundred twenty-one".