2181655 has 16 divisors (see below), whose sum is σ = 3032064. Its totient is φ = 1476000.

The previous prime is 2181649. The next prime is 2181659. The reversal of 2181655 is 5561812.

It is not a de Polignac number, because 2181655 - 2¹¹ = 2179607 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181659) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2530 + ... + 3280.

It is an arithmetic number, because the mean of its divisors is an integer number (189504).

2^2181655 is an apocalyptic number.

2181655 is a deficient number, since it is larger than the sum of its proper divisors (850409).

2181655 is an equidigital number, since it uses as much as digits as its factorization.

2181655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846.

The product of its digits is 2400, while the sum is 28.

The square root of 2181655 is about 1477.0426534126. The cubic root of 2181655 is about 129.6966298793.

The spelling of 2181655 in words is "two million, one hundred eighty-one thousand, six hundred fifty-five".