15909091 has 4 divisors (see below), whose sum is σ = 17355384. Its totient is φ = 14462800.

The previous prime is 15909079. The next prime is 15909151. The reversal of 15909091 is 19090951.

15909091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19090951 = 11 ⋅1735541.

It is not a de Polignac number, because 15909091 - 2⁹ = 15908579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15909391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 723130 + ... + 723151.

It is an arithmetic number, because the mean of its divisors is an integer number (4338846).

Almost surely, 2^15909091 is an apocalyptic number.

15909091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

15909091 is a deficient number, since it is larger than the sum of its proper divisors (1446293).

15909091 is a wasteful number, since it uses less digits than its factorization.

15909091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1446292.

The product of its (nonzero) digits is 3645, while the sum is 34.

The square root of 15909091 is about 3988.6201874834. The cubic root of 15909091 is about 251.5060609031.

The spelling of 15909091 in words is "fifteen million, nine hundred nine thousand, ninety-one".