15161991 has 16 divisors (see below), whose sum is σ = 22718976. Its totient is φ = 8924256.

The previous prime is 15161989. The next prime is 15162029. The reversal of 15161991 is 19916151.

It is not a de Polignac number, because 15161991 - 2¹ = 15161989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15161911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7555 + ... + 9348.

It is an arithmetic number, because the mean of its divisors is an integer number (1419936).

Almost surely, 2^15161991 is an apocalyptic number.

15161991 is a deficient number, since it is larger than the sum of its proper divisors (7556985).

15161991 is a wasteful number, since it uses less digits than its factorization.

15161991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16942.

The product of its digits is 2430, while the sum is 33.

The square root of 15161991 is about 3893.8401353933. The cubic root of 15161991 is about 247.5058176369.

The spelling of 15161991 in words is "fifteen million, one hundred sixty-one thousand, nine hundred ninety-one".