21338418 has 32 divisors (see below), whose sum is σ = 44115264. Its totient is φ = 6875712.

The previous prime is 21338357. The next prime is 21338431. The reversal of 21338418 is 81483312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61321 + ... + 61667.

It is an arithmetic number, because the mean of its divisors is an integer number (1378602).

Almost surely, 2^21338418 is an apocalyptic number.

21338418 is an abundant number, since it is smaller than the sum of its proper divisors (22776846).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21338418 is a wasteful number, since it uses less digits than its factorization.

21338418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666.

The product of its digits is 4608, while the sum is 30.

The square root of 21338418 is about 4619.3525520358. The cubic root of 21338418 is about 277.3665424334.

The spelling of 21338418 in words is "twenty-one million, three hundred thirty-eight thousand, four hundred eighteen".