18020491 has 8 divisors (see below), whose sum is σ = 18298368. Its totient is φ = 17745000.

The previous prime is 18020489. The next prime is 18020501. The reversal of 18020491 is 19402081.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 18020491 - 2¹ = 18020489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18020441) 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, 19326 + ... + 20236.

It is an arithmetic number, because the mean of its divisors is an integer number (2287296).

Almost surely, 2^18020491 is an apocalyptic number.

18020491 is a deficient number, since it is larger than the sum of its proper divisors (277877).

18020491 is a wasteful number, since it uses less digits than its factorization.

18020491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 18020491 is about 4245.0548877488. The cubic root of 18020491 is about 262.1735491376.

The spelling of 18020491 in words is "eighteen million, twenty thousand, four hundred ninety-one".