18972389 has 8 divisors (see below), whose sum is σ = 19323360. Its totient is φ = 18624496.

The previous prime is 18972383. The next prime is 18972413. The reversal of 18972389 is 98327981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18972389 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 (18972383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14219 + ... + 15495.

It is an arithmetic number, because the mean of its divisors is an integer number (2415420).

Almost surely, 2^18972389 is an apocalyptic number.

It is an amenable number.

18972389 is a deficient number, since it is larger than the sum of its proper divisors (350971).

18972389 is a wasteful number, since it uses less digits than its factorization.

18972389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539.

The product of its digits is 217728, while the sum is 47.

The square root of 18972389 is about 4355.7305931382. The cubic root of 18972389 is about 266.7108438963.

The spelling of 18972389 in words is "eighteen million, nine hundred seventy-two thousand, three hundred eighty-nine".