15421409 has 2 divisors, whose sum is σ = 15421410. Its totient is φ = 15421408.

The previous prime is 15421379. The next prime is 15421411. The reversal of 15421409 is 90412451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14992384 + 429025 = 3872^2 + 655^2 .

It is a cyclic number.

It is not a de Polignac number, because 15421409 - 2²⁰ = 14372833 is a prime.

Together with 15421411, 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 (15421309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7710704 + 7710705.

It is an arithmetic number, because the mean of its divisors is an integer number (7710705).

Almost surely, 2^15421409 is an apocalyptic number.

It is an amenable number.

15421409 is a deficient number, since it is larger than the sum of its proper divisors (1).

15421409 is an equidigital number, since it uses as much as digits as its factorization.

15421409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 15421409 is about 3927.0101858793. The cubic root of 15421409 is about 248.9094308870.

The spelling of 15421409 in words is "fifteen million, four hundred twenty-one thousand, four hundred nine".