2018681 has 4 divisors (see below), whose sum is σ = 2307072. Its totient is φ = 1730292.

The previous prime is 2018677. The next prime is 2018713. The reversal of 2018681 is 1868102.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1868102 = 2 ⋅934051.

It is a cyclic number.

It is not a de Polignac number, because 2018681 - 2² = 2018677 is a prime.

It is a super-2 number, since 2×2018681² = 8150145959522, 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 2018681.

It is not an unprimeable number, because it can be changed into a prime (2018651) 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, 144185 + ... + 144198.

It is an arithmetic number, because the mean of its divisors is an integer number (576768).

2^2018681 is an apocalyptic number.

It is an amenable number.

2018681 is a deficient number, since it is larger than the sum of its proper divisors (288391).

2018681 is an equidigital number, since it uses as much as digits as its factorization.

2018681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288390.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 2018681 is about 1420.8029420015. The cubic root of 2018681 is about 126.3831663543.

The spelling of 2018681 in words is "two million, eighteen thousand, six hundred eighty-one".