21994584 has 16 divisors (see below), whose sum is σ = 54986520. Its totient is φ = 7331520.

The previous prime is 21994561. The next prime is 21994589. The reversal of 21994584 is 48549912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21994589) 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 3 ways as a sum of consecutive naturals, for example, 458197 + ... + 458244.

Almost surely, 2^21994584 is an apocalyptic number.

21994584 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21994584 is an abundant number, since it is smaller than the sum of its proper divisors (32991936).

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

21994584 is a wasteful number, since it uses less digits than its factorization.

21994584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916450 (or 916446 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The square root of 21994584 is about 4689.8383767460. The cubic root of 21994584 is about 280.1809374738.

It can be divided in two parts, 21994 and 584, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 21994584 in words is "twenty-one million, nine hundred ninety-four thousand, five hundred eighty-four".