2187431 has 4 divisors (see below), whose sum is σ = 2215200. Its totient is φ = 2159664.

The previous prime is 2187421. The next prime is 2187457. The reversal of 2187431 is 1347812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2187431 is a prime.

It is a super-2 number, since 2×2187431² = 9569708759522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2187431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2187421) 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, 13766 + ... + 13923.

It is an arithmetic number, because the mean of its divisors is an integer number (553800).

2^2187431 is an apocalyptic number.

2187431 is a deficient number, since it is larger than the sum of its proper divisors (27769).

2187431 is an equidigital number, since it uses as much as digits as its factorization.

2187431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27768.

The product of its digits is 1344, while the sum is 26.

The square root of 2187431 is about 1478.9966193335. The cubic root of 2187431 is about 129.8109876478.

The spelling of 2187431 in words is "two million, one hundred eighty-seven thousand, four hundred thirty-one".