18116781 has 16 divisors (see below), whose sum is σ = 25819200. Its totient is φ = 11259648.

The previous prime is 18116767. The next prime is 18116789. The reversal of 18116781 is 18761181.

It is not a de Polignac number, because 18116781 - 2⁷ = 18116653 is a prime.

It is a super-2 number, since 2×18116781² = 656435507603922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18116789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3930 + ... + 7188.

It is an arithmetic number, because the mean of its divisors is an integer number (1613700).

Almost surely, 2^18116781 is an apocalyptic number.

It is an amenable number.

18116781 is a deficient number, since it is larger than the sum of its proper divisors (7702419).

18116781 is a wasteful number, since it uses less digits than its factorization.

18116781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3388.

The product of its digits is 2688, while the sum is 33.

The square root of 18116781 is about 4256.3812094313. The cubic root of 18116781 is about 262.6396825745.

The spelling of 18116781 in words is "eighteen million, one hundred sixteen thousand, seven hundred eighty-one".