21984545 has 8 divisors (see below), whose sum is σ = 28779840. Its totient is φ = 15988720.

The previous prime is 21984533. The next prime is 21984593. The reversal of 21984545 is 54548912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21984545 - 2¹² = 21980449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21984499 and 21984508.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 199805 + ... + 199914.

It is an arithmetic number, because the mean of its divisors is an integer number (3597480).

Almost surely, 2^21984545 is an apocalyptic number.

It is an amenable number.

21984545 is a deficient number, since it is larger than the sum of its proper divisors (6795295).

21984545 is a wasteful number, since it uses less digits than its factorization.

21984545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399735.

The product of its digits is 57600, while the sum is 38.

The square root of 21984545 is about 4688.7679618424. The cubic root of 21984545 is about 280.1383032738.

The spelling of 21984545 in words is "twenty-one million, nine hundred eighty-four thousand, five hundred forty-five".