15091891 has 2 divisors, whose sum is σ = 15091892. Its totient is φ = 15091890.

The previous prime is 15091889. The next prime is 15091931. The reversal of 15091891 is 19819051.

15091891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15091891 - 2¹ = 15091889 is a prime.

Together with 15091889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15091991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7545945 + 7545946.

It is an arithmetic number, because the mean of its divisors is an integer number (7545946).

Almost surely, 2^15091891 is an apocalyptic number.

15091891 is a deficient number, since it is larger than the sum of its proper divisors (1).

15091891 is an equidigital number, since it uses as much as digits as its factorization.

15091891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 34.

The square root of 15091891 is about 3884.8283102346. The cubic root of 15091891 is about 247.1237885302.

The spelling of 15091891 in words is "fifteen million, ninety-one thousand, eight hundred ninety-one".