18981093 has 12 divisors (see below), whose sum is σ = 25719360. Its totient is φ = 12449736.

The previous prime is 18981089. The next prime is 18981107. The reversal of 18981093 is 39018981.

It is a happy number.

It is not a de Polignac number, because 18981093 - 2² = 18981089 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18981023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66930 + ... + 67212.

It is an arithmetic number, because the mean of its divisors is an integer number (2143280).

Almost surely, 2^18981093 is an apocalyptic number.

It is an amenable number.

18981093 is a deficient number, since it is larger than the sum of its proper divisors (6738267).

18981093 is an frugal number, since it uses more digits than its factorization.

18981093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648 (or 365 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 18981093 is about 4356.7296220904. The cubic root of 18981093 is about 266.7516241458.

The spelling of 18981093 in words is "eighteen million, nine hundred eighty-one thousand, ninety-three".