18997287 has 8 divisors (see below), whose sum is σ = 26431104. Its totient is φ = 12114168.

The previous prime is 18997273. The next prime is 18997331. The reversal of 18997287 is 78279981.

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

It is not a de Polignac number, because 18997287 - 2⁸ = 18997031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18997087) 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, 137593 + ... + 137730.

It is an arithmetic number, because the mean of its divisors is an integer number (3303888).

Almost surely, 2^18997287 is an apocalyptic number.

18997287 is a deficient number, since it is larger than the sum of its proper divisors (7433817).

18997287 is a wasteful number, since it uses less digits than its factorization.

18997287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275349.

The product of its digits is 508032, while the sum is 51.

The square root of 18997287 is about 4358.5877299878. The cubic root of 18997287 is about 266.8274636121.

The spelling of 18997287 in words is "eighteen million, nine hundred ninety-seven thousand, two hundred eighty-seven".