15591399 has 12 divisors (see below), whose sum is σ = 21161016. Its totient is φ = 10211248.

The previous prime is 15591383. The next prime is 15591421. The reversal of 15591399 is 99319551.

It is not a de Polignac number, because 15591399 - 2⁴ = 15591383 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15591399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15591349) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9697 + ... + 11189.

It is an arithmetic number, because the mean of its divisors is an integer number (1763418).

Almost surely, 2^15591399 is an apocalyptic number.

15591399 is a deficient number, since it is larger than the sum of its proper divisors (5569617).

15591399 is an equidigital number, since it uses as much as digits as its factorization.

15591399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1614 (or 1555 counting only the distinct ones).

The product of its digits is 54675, while the sum is 42.

The square root of 15591399 is about 3948.5945600935. The cubic root of 15591399 is about 249.8206660548.

The spelling of 15591399 in words is "fifteen million, five hundred ninety-one thousand, three hundred ninety-nine".