18720873 has 12 divisors (see below), whose sum is σ = 28217280. Its totient is φ = 11937816.

The previous prime is 18720847. The next prime is 18720881. The reversal of 18720873 is 37802781.

It is not a de Polignac number, because 18720873 - 2¹⁰ = 18719849 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18720803) 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, 45013 + ... + 45426.

It is an arithmetic number, because the mean of its divisors is an integer number (2351440).

Almost surely, 2^18720873 is an apocalyptic number.

It is an amenable number.

18720873 is a deficient number, since it is larger than the sum of its proper divisors (9496407).

18720873 is a wasteful number, since it uses less digits than its factorization.

18720873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90468 (or 90465 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 18720873 is about 4326.7624154788. The cubic root of 18720873 is about 265.5270063073.

The spelling of 18720873 in words is "eighteen million, seven hundred twenty thousand, eight hundred seventy-three".