18808993 has 24 divisors (see below), whose sum is σ = 23392800. Its totient is φ = 15035328.

The previous prime is 18808991. The next prime is 18808997. The reversal of 18808993 is 39980881.

It is not a de Polignac number, because 18808993 - 2¹ = 18808991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18808991) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82746 + ... + 82972.

It is an arithmetic number, because the mean of its divisors is an integer number (974700).

Almost surely, 2^18808993 is an apocalyptic number.

It is an amenable number.

18808993 is a deficient number, since it is larger than the sum of its proper divisors (4583807).

18808993 is a wasteful number, since it uses less digits than its factorization.

18808993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 18808993 is about 4336.9335941423. The cubic root of 18808993 is about 265.9429702300.

The spelling of 18808993 in words is "eighteen million, eight hundred eight thousand, nine hundred ninety-three".