18921489 has 8 divisors (see below), whose sum is σ = 25512480. Its totient is φ = 12472416.

The previous prime is 18921457. The next prime is 18921503. The reversal of 18921489 is 98412981.

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

It is not a de Polignac number, because 18921489 - 2⁵ = 18921457 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18921489.

It is not an unprimeable number, because it can be changed into a prime (18921449) 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, 35167 + ... + 35700.

It is an arithmetic number, because the mean of its divisors is an integer number (3189060).

Almost surely, 2^18921489 is an apocalyptic number.

It is an amenable number.

18921489 is a deficient number, since it is larger than the sum of its proper divisors (6590991).

18921489 is an equidigital number, since it uses as much as digits as its factorization.

18921489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70959.

The product of its digits is 41472, while the sum is 42.

The square root of 18921489 is about 4349.8837915512. The cubic root of 18921489 is about 266.4721155618.

The spelling of 18921489 in words is "eighteen million, nine hundred twenty-one thousand, four hundred eighty-nine".