2155868 has 24 divisors (see below), whose sum is σ = 4433520. Its totient is φ = 904320.

The previous prime is 2155861. The next prime is 2155877. The reversal of 2155868 is 8685512.

It is a happy number.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1313 + ... + 2456.

It is an arithmetic number, because the mean of its divisors is an integer number (184730).

2^2155868 is an apocalyptic number.

It is an amenable number.

2155868 is an abundant number, since it is smaller than the sum of its proper divisors (2277652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2155868 is a wasteful number, since it uses less digits than its factorization.

2155868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3797 (or 3795 counting only the distinct ones).

The product of its digits is 19200, while the sum is 35.

The square root of 2155868 is about 1468.2874377996. The cubic root of 2155868 is about 129.1836017106.

The spelling of 2155868 in words is "two million, one hundred fifty-five thousand, eight hundred sixty-eight".