15591649 has 2 divisors, whose sum is σ = 15591650. Its totient is φ = 15591648.

The previous prime is 15591623. The next prime is 15591659. The reversal of 15591649 is 94619551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10497600 + 5094049 = 3240^2 + 2257^2 .

It is a cyclic number.

It is not a de Polignac number, because 15591649 - 2⁵ = 15591617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15591659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7795824 + 7795825.

It is an arithmetic number, because the mean of its divisors is an integer number (7795825).

Almost surely, 2^15591649 is an apocalyptic number.

It is an amenable number.

15591649 is a deficient number, since it is larger than the sum of its proper divisors (1).

15591649 is an equidigital number, since it uses as much as digits as its factorization.

15591649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48600, while the sum is 40.

The square root of 15591649 is about 3948.6262168000. The cubic root of 15591649 is about 249.8220012959.

The spelling of 15591649 in words is "fifteen million, five hundred ninety-one thousand, six hundred forty-nine".