2181291 has 16 divisors (see below), whose sum is σ = 3345408. Its totient is φ = 1238400.

The previous prime is 2181271. The next prime is 2181329. The reversal of 2181291 is 1921812.

It is not a de Polignac number, because 2181291 - 2⁵ = 2181259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2181271) 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, 4846 + ... + 5276.

It is an arithmetic number, because the mean of its divisors is an integer number (209088).

2^2181291 is an apocalyptic number.

2181291 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2181291 is a deficient number, since it is larger than the sum of its proper divisors (1164117).

2181291 is a wasteful number, since it uses less digits than its factorization.

2181291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682.

The product of its digits is 288, while the sum is 24.

The square root of 2181291 is about 1476.9194290820. The cubic root of 2181291 is about 129.6894163650.

It can be divided in two parts, 218129 and 1, that added together give a triangular number (218130 = T₆₆₀).

The spelling of 2181291 in words is "two million, one hundred eighty-one thousand, two hundred ninety-one".