2188681 has 4 divisors (see below), whose sum is σ = 2387664. Its totient is φ = 1989700.

The previous prime is 2188679. The next prime is 2188687. The reversal of 2188681 is 1868812.

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 2188681 - 2¹ = 2188679 is a prime.

It is a super-2 number, since 2×2188681² = 9580649039522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2188687) 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, 99475 + ... + 99496.

It is an arithmetic number, because the mean of its divisors is an integer number (596916).

2^2188681 is an apocalyptic number.

It is an amenable number.

2188681 is a deficient number, since it is larger than the sum of its proper divisors (198983).

2188681 is a wasteful number, since it uses less digits than its factorization.

2188681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198982.

The product of its digits is 6144, while the sum is 34.

The square root of 2188681 is about 1479.4191427719. The cubic root of 2188681 is about 129.8357096216.

The spelling of 2188681 in words is "two million, one hundred eighty-eight thousand, six hundred eighty-one".