2187631 has 4 divisors (see below), whose sum is σ = 2214072. Its totient is φ = 2161192.

The previous prime is 2187629. The next prime is 2187667. The reversal of 2187631 is 1367812.

2187631 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2187631 - 2¹ = 2187629 is a prime.

It is a super-2 number, since 2×2187631² = 9571458784322, 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 2187631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2187671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13096 + ... + 13261.

It is an arithmetic number, because the mean of its divisors is an integer number (553518).

2^2187631 is an apocalyptic number.

2187631 is a deficient number, since it is larger than the sum of its proper divisors (26441).

2187631 is an equidigital number, since it uses as much as digits as its factorization.

2187631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26440.

The product of its digits is 2016, while the sum is 28.

The square root of 2187631 is about 1479.0642311948. The cubic root of 2187631 is about 129.8149437964.

The spelling of 2187631 in words is "two million, one hundred eighty-seven thousand, six hundred thirty-one".