2181237 has 4 divisors (see below), whose sum is σ = 2908320. Its totient is φ = 1454156.

The previous prime is 2181233. The next prime is 2181247. The reversal of 2181237 is 7321812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2181237 - 2² = 2181233 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181233) 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, 363537 + ... + 363542.

It is an arithmetic number, because the mean of its divisors is an integer number (727080).

2^2181237 is an apocalyptic number.

It is an amenable number.

2181237 is a deficient number, since it is larger than the sum of its proper divisors (727083).

2181237 is an equidigital number, since it uses as much as digits as its factorization.

2181237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727082.

The product of its digits is 672, while the sum is 24.

The square root of 2181237 is about 1476.9011476737. The cubic root of 2181237 is about 129.6883461599.

It can be divided in two parts, 218123 and 7, that added together give a triangular number (218130 = T₆₆₀).

The spelling of 2181237 in words is "two million, one hundred eighty-one thousand, two hundred thirty-seven".