18140781 has 8 divisors (see below), whose sum is σ = 24459840. Its totient is φ = 11957792.

The previous prime is 18140779. The next prime is 18140783. The reversal of 18140781 is 18704181.

It is an interprime number because it is at equal distance from previous prime (18140779) and next prime (18140783).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18140781 - 2¹ = 18140779 is a prime.

It is a super-2 number, since 2×18140781² = 658175870579922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18140783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33705 + ... + 34238.

It is an arithmetic number, because the mean of its divisors is an integer number (3057480).

Almost surely, 2^18140781 is an apocalyptic number.

It is an amenable number.

18140781 is a deficient number, since it is larger than the sum of its proper divisors (6319059).

18140781 is an equidigital number, since it uses as much as digits as its factorization.

18140781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68035.

The product of its (nonzero) digits is 1792, while the sum is 30.

The square root of 18140781 is about 4259.1995726897. The cubic root of 18140781 is about 262.7556077122.

The spelling of 18140781 in words is "eighteen million, one hundred forty thousand, seven hundred eighty-one".