15913649 has 4 divisors (see below), whose sum is σ = 16849764. Its totient is φ = 14977536.

The previous prime is 15913643. The next prime is 15913669. The reversal of 15913649 is 94631951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94631951 = 19 ⋅4980629.

It can be written as a sum of positive squares in 2 ways, for example, as 8596624 + 7317025 = 2932^2 + 2705^2 .

It is a cyclic number.

It is not a de Polignac number, because 15913649 - 2²⁰ = 14865073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15913643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468032 + ... + 468065.

It is an arithmetic number, because the mean of its divisors is an integer number (4212441).

Almost surely, 2^15913649 is an apocalyptic number.

It is an amenable number.

15913649 is a deficient number, since it is larger than the sum of its proper divisors (936115).

15913649 is an equidigital number, since it uses as much as digits as its factorization.

15913649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936114.

The product of its digits is 29160, while the sum is 38.

The square root of 15913649 is about 3989.1915221007. The cubic root of 15913649 is about 251.5300776779.

The spelling of 15913649 in words is "fifteen million, nine hundred thirteen thousand, six hundred forty-nine".