2155866 has 8 divisors (see below), whose sum is σ = 4311744. Its totient is φ = 718620.

The previous prime is 2155861. The next prime is 2155877. The reversal of 2155866 is 6685512.

It is a sphenic number, since it is the product of 3 distinct primes.

2155866 is an admirable number.

It is an Ulam 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 3 ways as a sum of consecutive naturals, for example, 179650 + ... + 179661.

It is an arithmetic number, because the mean of its divisors is an integer number (538968).

2^2155866 is an apocalyptic number.

2155866 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2155866 is a wasteful number, since it uses less digits than its factorization.

2155866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359316.

The product of its digits is 14400, while the sum is 33.

The square root of 2155866 is about 1468.2867567338. The cubic root of 2155866 is about 129.1835617627.

The spelling of 2155866 in words is "two million, one hundred fifty-five thousand, eight hundred sixty-six".