18138769 has 16 divisors (see below), whose sum is σ = 20837376. Its totient is φ = 15638400.

The previous prime is 18138767. The next prime is 18138797. The reversal of 18138769 is 96783181.

It is a cyclic number.

It is not a de Polignac number, because 18138769 - 2¹ = 18138767 is a prime.

It is a super-2 number, since 2×18138769² = 658029881670722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18138767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16144 + ... + 17230.

It is an arithmetic number, because the mean of its divisors is an integer number (1302336).

Almost surely, 2^18138769 is an apocalyptic number.

It is an amenable number.

18138769 is a deficient number, since it is larger than the sum of its proper divisors (2698607).

18138769 is a wasteful number, since it uses less digits than its factorization.

18138769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1176.

The product of its digits is 72576, while the sum is 43.

The square root of 18138769 is about 4258.9633715260. The cubic root of 18138769 is about 262.7458932493.

The spelling of 18138769 in words is "eighteen million, one hundred thirty-eight thousand, seven hundred sixty-nine".