2155931 has 2 divisors, whose sum is σ = 2155932. Its totient is φ = 2155930.

The previous prime is 2155883. The next prime is 2155961. The reversal of 2155931 is 1395512.

2155931 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 2155931 - 2¹⁰ = 2154907 is a prime.

It is a super-2 number, since 2×2155931² = 9296076953522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2155931.

It is not a weakly prime, because it can be changed into another prime (2155961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077965 + 1077966.

It is an arithmetic number, because the mean of its divisors is an integer number (1077966).

2^2155931 is an apocalyptic number.

2155931 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155931 is an equidigital number, since it uses as much as digits as its factorization.

2155931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1350, while the sum is 26.

The square root of 2155931 is about 1468.3088912078. The cubic root of 2155931 is about 129.1848600573.

The spelling of 2155931 in words is "two million, one hundred fifty-five thousand, nine hundred thirty-one".