15955891 has 4 divisors (see below), whose sum is σ = 18235312. Its totient is φ = 13676472.

The previous prime is 15955871. The next prime is 15955909. The reversal of 15955891 is 19855951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19855951 = 1321 ⋅15031.

It is a cyclic number.

It is not a de Polignac number, because 15955891 - 2¹³ = 15947699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15955811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1139700 + ... + 1139713.

It is an arithmetic number, because the mean of its divisors is an integer number (4558828).

Almost surely, 2^15955891 is an apocalyptic number.

15955891 is a deficient number, since it is larger than the sum of its proper divisors (2279421).

15955891 is an equidigital number, since it uses as much as digits as its factorization.

15955891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2279420.

The product of its digits is 81000, while the sum is 43.

The square root of 15955891 is about 3994.4825697454. The cubic root of 15955891 is about 251.7524391254.

The spelling of 15955891 in words is "fifteen million, nine hundred fifty-five thousand, eight hundred ninety-one".