21984590 has 16 divisors (see below), whose sum is σ = 39705120. Its totient is φ = 8764320.

The previous prime is 21984533. The next prime is 21984593. The reversal of 21984590 is 9548912.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21984593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425 + ... + 6644.

It is an arithmetic number, because the mean of its divisors is an integer number (2481570).

Almost surely, 2^21984590 is an apocalyptic number.

21984590 is a deficient number, since it is larger than the sum of its proper divisors (17720530).

21984590 is a wasteful number, since it uses less digits than its factorization.

21984590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7387.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 21984590 is about 4688.7727605419. The cubic root of 21984590 is about 280.1384944114.

The spelling of 21984590 in words is "twenty-one million, nine hundred eighty-four thousand, five hundred ninety".