15449921 has 2 divisors, whose sum is σ = 15449922. Its totient is φ = 15449920.

The previous prime is 15449911. The next prime is 15449927. The reversal of 15449921 is 12994451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15366400 + 83521 = 3920^2 + 289^2 .

It is an emirp because it is prime and its reverse (12994451) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15449921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15449927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7724960 + 7724961.

It is an arithmetic number, because the mean of its divisors is an integer number (7724961).

Almost surely, 2^15449921 is an apocalyptic number.

It is an amenable number.

15449921 is a deficient number, since it is larger than the sum of its proper divisors (1).

15449921 is an equidigital number, since it uses as much as digits as its factorization.

15449921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 35.

The square root of 15449921 is about 3930.6387521623. The cubic root of 15449921 is about 249.0627358683.

The spelling of 15449921 in words is "fifteen million, four hundred forty-nine thousand, nine hundred twenty-one".