18016281 has 6 divisors (see below), whose sum is σ = 26023530. Its totient is φ = 12010848.

The previous prime is 18016267. The next prime is 18016303. The reversal of 18016281 is 18261081.

It can be written as a sum of positive squares in only one way, i.e., 11964681 + 6051600 = 3459^2 + 2460^2 .

It is not a de Polignac number, because 18016281 - 2⁵ = 18016249 is a prime.

It is a super-2 number, since 2×18016281² = 649172762141922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18016681) 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, 1000896 + ... + 1000913.

It is an arithmetic number, because the mean of its divisors is an integer number (4337255).

Almost surely, 2^18016281 is an apocalyptic number.

It is an amenable number.

18016281 is a deficient number, since it is larger than the sum of its proper divisors (8007249).

18016281 is a wasteful number, since it uses less digits than its factorization.

18016281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001815 (or 2001812 counting only the distinct ones).

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

The square root of 18016281 is about 4244.5589876924. The cubic root of 18016281 is about 262.1531309628.

It can be divided in two parts, 180 and 16281, that added together give a palindrome (16461).

The spelling of 18016281 in words is "eighteen million, sixteen thousand, two hundred eighty-one".