18490681 has 8 divisors (see below), whose sum is σ = 20448864. Its totient is φ = 16578720.

The previous prime is 18490673. The next prime is 18490691. The reversal of 18490681 is 18609481.

It is a happy number.

It is the 1756-th star number.

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 18490681 - 2³ = 18490673 is a prime.

It is a super-2 number, since 2×18490681² = 683810567687522, 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 18490681.

It is not an unprimeable number, because it can be changed into a prime (18490691) 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 7 ways as a sum of consecutive naturals, for example, 10711 + ... + 12316.

It is an arithmetic number, because the mean of its divisors is an integer number (2556108).

Almost surely, 2^18490681 is an apocalyptic number.

18490681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18490681 is a deficient number, since it is larger than the sum of its proper divisors (1958183).

18490681 is a wasteful number, since it uses less digits than its factorization.

18490681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23111.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 18490681 is about 4300.0791853174. The cubic root of 18490681 is about 264.4342075941.

The spelling of 18490681 in words is "eighteen million, four hundred ninety thousand, six hundred eighty-one".