15091609 has 4 divisors (see below), whose sum is σ = 16252516. Its totient is φ = 13930704.

The previous prime is 15091561. The next prime is 15091619. The reversal of 15091609 is 90619051.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90619051 = 1489 ⋅60859.

It can be written as a sum of positive squares in 2 ways, for example, as 3168400 + 11923209 = 1780^2 + 3453^2 .

It is a cyclic number.

It is not a de Polignac number, because 15091609 - 2²³ = 6703001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15091619) 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, 580434 + ... + 580459.

It is an arithmetic number, because the mean of its divisors is an integer number (4063129).

Almost surely, 2^15091609 is an apocalyptic number.

It is an amenable number.

15091609 is a deficient number, since it is larger than the sum of its proper divisors (1160907).

15091609 is a wasteful number, since it uses less digits than its factorization.

15091609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1160906.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 15091609 is about 3884.7920150247. The cubic root of 15091609 is about 247.1222493075.

The spelling of 15091609 in words is "fifteen million, ninety-one thousand, six hundred nine".