18289997 has 6 divisors (see below), whose sum is σ = 20104014. Its totient is φ = 16627160.

The previous prime is 18289993. The next prime is 18290017. The reversal of 18289997 is 79998281.

It can be written as a sum of positive squares in only one way, i.e., 13498276 + 4791721 = 3674^2 + 2189^2 .

It is not a de Polignac number, because 18289997 - 2² = 18289993 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 (18289993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75458 + ... + 75699.

It is an arithmetic number, because the mean of its divisors is an integer number (3350669).

Almost surely, 2^18289997 is an apocalyptic number.

It is an amenable number.

18289997 is a deficient number, since it is larger than the sum of its proper divisors (1814017).

18289997 is a wasteful number, since it uses less digits than its factorization.

18289997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151179 (or 151168 counting only the distinct ones).

The product of its digits is 653184, while the sum is 53.

The square root of 18289997 is about 4276.6806053293. The cubic root of 18289997 is about 263.4740686951.

The spelling of 18289997 in words is "eighteen million, two hundred eighty-nine thousand, nine hundred ninety-seven".