2155881 has 32 divisors (see below), whose sum is σ = 3628800. Its totient is φ = 1108224.

The previous prime is 2155877. The next prime is 2155883. The reversal of 2155881 is 1885512.

It is not a de Polignac number, because 2155881 - 2² = 2155877 is a prime.

It is a super-2 number, since 2×2155881² = 9295645772322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2155883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14395 + ... + 14543.

It is an arithmetic number, because the mean of its divisors is an integer number (113400).

2^2155881 is an apocalyptic number.

2155881 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2155881 is a deficient number, since it is larger than the sum of its proper divisors (1472919).

2155881 is a wasteful number, since it uses less digits than its factorization.

2155881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225.

The product of its digits is 3200, while the sum is 30.

The square root of 2155881 is about 1468.2918647190. The cubic root of 2155881 is about 129.1838613715.

The spelling of 2155881 in words is "two million, one hundred fifty-five thousand, eight hundred eighty-one".