15859891 has 2 divisors, whose sum is σ = 15859892. Its totient is φ = 15859890.

The previous prime is 15859871. The next prime is 15859901. The reversal of 15859891 is 19895851.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15859891 - 2⁵ = 15859859 is a prime.

It is a super-2 number, since 2×15859891² = 503072285063762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (15859871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7929945 + 7929946.

It is an arithmetic number, because the mean of its divisors is an integer number (7929946).

Almost surely, 2^15859891 is an apocalyptic number.

15859891 is a deficient number, since it is larger than the sum of its proper divisors (1).

15859891 is an equidigital number, since it uses as much as digits as its factorization.

15859891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 46.

The square root of 15859891 is about 3982.4478653210. The cubic root of 15859891 is about 251.2465263581.

It can be divided in two parts, 1585 and 9891, that added together give a triangular number (11476 = T₁₅₁).

The spelling of 15859891 in words is "fifteen million, eight hundred fifty-nine thousand, eight hundred ninety-one".