21338430 has 32 divisors (see below), whose sum is σ = 51470208. Its totient is φ = 5661600.

The previous prime is 21338357. The next prime is 21338431. The reversal of 21338430 is 3483312.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21338430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21338431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4645 + ... + 8015.

It is an arithmetic number, because the mean of its divisors is an integer number (1608444).

Almost surely, 2^21338430 is an apocalyptic number.

21338430 is an abundant number, since it is smaller than the sum of its proper divisors (30131778).

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

21338430 is a wasteful number, since it uses less digits than its factorization.

21338430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3592.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 21338430 is about 4619.3538509190. The cubic root of 21338430 is about 277.3665944272.

The spelling of 21338430 in words is "twenty-one million, three hundred thirty-eight thousand, four hundred thirty".