18400906 has 8 divisors (see below), whose sum is σ = 28553220. Its totient is φ = 8883168.

The previous prime is 18400901. The next prime is 18400909. The reversal of 18400906 is 60900481.

It can be written as a sum of positive squares in 2 ways, for example, as 18190225 + 210681 = 4265^2 + 459^2 .

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

It is not an unprimeable number, because it can be changed into a prime (18400901) 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, 158571 + ... + 158686.

Almost surely, 2^18400906 is an apocalyptic number.

18400906 is a deficient number, since it is larger than the sum of its proper divisors (10152314).

18400906 is a wasteful number, since it uses less digits than its factorization.

18400906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317288.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 18400906 is about 4289.6277227750. The cubic root of 18400906 is about 264.0055573516.

It can be divided in two parts, 18400 and 906, that added together give a triangular number (19306 = T₁₉₆).

The spelling of 18400906 in words is "eighteen million, four hundred thousand, nine hundred six".