2155905 has 24 divisors (see below), whose sum is σ = 3901248. Its totient is φ = 1099296.

The previous prime is 2155883. The next prime is 2155931. The reversal of 2155905 is 5095512.

It is not a de Polignac number, because 2155905 - 2⁶ = 2155841 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7 + ... + 2076.

It is an arithmetic number, because the mean of its divisors is an integer number (162552).

2^2155905 is an apocalyptic number.

It is an amenable number.

2155905 is a deficient number, since it is larger than the sum of its proper divisors (1745343).

2155905 is a wasteful number, since it uses less digits than its factorization.

2155905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117 (or 2114 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 2155905 is about 1468.3000374583. The cubic root of 2155905 is about 129.1843407426.

The spelling of 2155905 in words is "two million, one hundred fifty-five thousand, nine hundred five".