2118281 has 4 divisors (see below), whose sum is σ = 2310864. Its totient is φ = 1925700.

The previous prime is 2118269. The next prime is 2118283. The reversal of 2118281 is 1828112.

It is a happy number.

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 2118281 - 2¹⁸ = 1856137 is a prime.

It is a super-2 number, since 2×2118281² = 8974228789922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2118283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96275 + ... + 96296.

It is an arithmetic number, because the mean of its divisors is an integer number (577716).

2^2118281 is an apocalyptic number.

It is an amenable number.

2118281 is a deficient number, since it is larger than the sum of its proper divisors (192583).

2118281 is a wasteful number, since it uses less digits than its factorization.

2118281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192582.

The product of its digits is 256, while the sum is 23.

The square root of 2118281 is about 1455.4315511215. The cubic root of 2118281 is about 128.4284349702.

The spelling of 2118281 in words is "two million, one hundred eighteen thousand, two hundred eighty-one".