18012681 has 6 divisors (see below), whose sum is σ = 26018330. Its totient is φ = 12008448.

The previous prime is 18012679. The next prime is 18012691. The reversal of 18012681 is 18621081.

It can be written as a sum of positive squares in only one way, i.e., 16941456 + 1071225 = 4116^2 + 1035^2 .

It is not a de Polignac number, because 18012681 - 2¹ = 18012679 is a prime.

It is a super-2 number, since 2×18012681² = 648913353615522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18012661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1000696 + ... + 1000713.

Almost surely, 2^18012681 is an apocalyptic number.

It is an amenable number.

18012681 is a deficient number, since it is larger than the sum of its proper divisors (8005649).

18012681 is a wasteful number, since it uses less digits than its factorization.

18012681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001415 (or 2001412 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 18012681 is about 4244.1348941804. The cubic root of 18012681 is about 262.1356687178.

Subtracting 18012681 from its reverse (18621081), we obtain a square (608400 = 780²).

The spelling of 18012681 in words is "eighteen million, twelve thousand, six hundred eighty-one".