18681093 has 6 divisors (see below), whose sum is σ = 26983814. Its totient is φ = 12454056.

The previous prime is 18681053. The next prime is 18681139. The reversal of 18681093 is 39018681.

It can be written as a sum of positive squares in only one way, i.e., 18507204 + 173889 = 4302^2 + 417^2 .

It is not a de Polignac number, because 18681093 - 2⁶ = 18681029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18681053) 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, 1037830 + ... + 1037847.

Almost surely, 2^18681093 is an apocalyptic number.

It is an amenable number.

18681093 is a deficient number, since it is larger than the sum of its proper divisors (8302721).

18681093 is a wasteful number, since it uses less digits than its factorization.

18681093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075683 (or 2075680 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 18681093 is about 4322.1630001655. The cubic root of 18681093 is about 265.3388000790.

The spelling of 18681093 in words is "eighteen million, six hundred eighty-one thousand, ninety-three".