18149869 has 4 divisors (see below), whose sum is σ = 18640444. Its totient is φ = 17659296.

The previous prime is 18149867. The next prime is 18149881. The reversal of 18149869 is 96894181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17222500 + 927369 = 4150^2 + 963^2 .

It is a cyclic number.

It is not a de Polignac number, because 18149869 - 2¹ = 18149867 is a prime.

It is a super-2 number, since 2×18149869² = 658835489434322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18149861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 245232 + ... + 245305.

It is an arithmetic number, because the mean of its divisors is an integer number (4660111).

Almost surely, 2^18149869 is an apocalyptic number.

It is an amenable number.

18149869 is a deficient number, since it is larger than the sum of its proper divisors (490575).

18149869 is an equidigital number, since it uses as much as digits as its factorization.

18149869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490574.

The product of its digits is 124416, while the sum is 46.

The square root of 18149869 is about 4260.2663062302. The cubic root of 18149869 is about 262.7994780085.

The spelling of 18149869 in words is "eighteen million, one hundred forty-nine thousand, eight hundred sixty-nine".