18126649 has 4 divisors (see below), whose sum is σ = 18397264. Its totient is φ = 17856036.

The previous prime is 18126643. The next prime is 18126659. The reversal of 18126649 is 94662181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18126649 - 2¹⁷ = 17995577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18126643) 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, 135207 + ... + 135340.

It is an arithmetic number, because the mean of its divisors is an integer number (4599316).

Almost surely, 2^18126649 is an apocalyptic number.

It is an amenable number.

18126649 is a deficient number, since it is larger than the sum of its proper divisors (270615).

18126649 is an equidigital number, since it uses as much as digits as its factorization.

18126649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270614.

The product of its digits is 20736, while the sum is 37.

The square root of 18126649 is about 4257.5402523053. The cubic root of 18126649 is about 262.6873595131.

The spelling of 18126649 in words is "eighteen million, one hundred twenty-six thousand, six hundred forty-nine".