21894738 has 16 divisors (see below), whose sum is σ = 44858016. Its totient is φ = 7120160.

The previous prime is 21894737. The next prime is 21894751. The reversal of 21894738 is 83749812.

It is a self number, because there is not a number n which added to its sum of digits gives 21894738.

It is not an unprimeable number, because it can be changed into a prime (21894737) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 44256 + ... + 44747.

It is an arithmetic number, because the mean of its divisors is an integer number (2803626).

Almost surely, 2^21894738 is an apocalyptic number.

21894738 is an abundant number, since it is smaller than the sum of its proper divisors (22963278).

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

21894738 is a wasteful number, since it uses less digits than its factorization.

21894738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89049.

The product of its digits is 96768, while the sum is 42.

The square root of 21894738 is about 4679.1813386532. The cubic root of 21894738 is about 279.7563271183.

The spelling of 21894738 in words is "twenty-one million, eight hundred ninety-four thousand, seven hundred thirty-eight".