2156091 has 16 divisors (see below), whose sum is σ = 3327744. Its totient is φ = 1216224.

The previous prime is 2156087. The next prime is 2156111. The reversal of 2156091 is 1906512.

2156091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2156091 - 2² = 2156087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2156041) 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 in 15 ways as a sum of consecutive naturals, for example, 1125 + ... + 2361.

It is an arithmetic number, because the mean of its divisors is an integer number (207984).

2^2156091 is an apocalyptic number.

2156091 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2156091 is a deficient number, since it is larger than the sum of its proper divisors (1171653).

2156091 is a wasteful number, since it uses less digits than its factorization.

2156091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 2156091 is about 1468.3633746454. The cubic root of 2156091 is about 129.1880557480.

The spelling of 2156091 in words is "two million, one hundred fifty-six thousand, ninety-one".