155891 has 2 divisors, whose sum is σ = 155892. Its totient is φ = 155890.

The previous prime is 155887. The next prime is 155893. The reversal of 155891 is 198551.

155891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155891 - 2² = 155887 is a prime.

Together with 155893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (155893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77945 + 77946.

It is an arithmetic number, because the mean of its divisors is an integer number (77946).

2¹⁵⁵⁸⁹¹ is an apocalyptic number.

155891 is a deficient number, since it is larger than the sum of its proper divisors (1).

155891 is an equidigital number, since it uses as much as digits as its factorization.

155891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1800, while the sum is 29.

The square root of 155891 is about 394.8303433122. The cubic root of 155891 is about 53.8195853754.

It can be divided in two parts, 1558 and 91, that multiplied together give a triangular number (141778 = T₅₃₂).

The spelling of 155891 in words is "one hundred fifty-five thousand, eight hundred ninety-one".