2155815 has 20 divisors (see below), whose sum is σ = 3865224. Its totient is φ = 1149552.

The previous prime is 2155799. The next prime is 2155837. The reversal of 2155815 is 5185512.

It is not a de Polignac number, because 2155815 - 2⁴ = 2155799 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2257 + ... + 3066.

2^2155815 is an apocalyptic number.

2155815 is a deficient number, since it is larger than the sum of its proper divisors (1709409).

2155815 is an equidigital number, since it uses as much as digits as its factorization.

2155815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5340 (or 5331 counting only the distinct ones).

The product of its digits is 2000, while the sum is 27.

The square root of 2155815 is about 1468.2693894514. The cubic root of 2155815 is about 129.1825430826.

The spelling of 2155815 in words is "two million, one hundred fifty-five thousand, eight hundred fifteen".