21982785 has 48 divisors (see below), whose sum is σ = 40848192. Its totient is φ = 10009600.

The previous prime is 21982781. The next prime is 21982787. The reversal of 21982785 is 58728912.

It is not a de Polignac number, because 21982785 - 2² = 21982781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21982781) 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 47 ways as a sum of consecutive naturals, for example, 47455 + ... + 47915.

It is an arithmetic number, because the mean of its divisors is an integer number (851004).

Almost surely, 2^21982785 is an apocalyptic number.

It is an amenable number.

21982785 is a deficient number, since it is larger than the sum of its proper divisors (18865407).

21982785 is a wasteful number, since it uses less digits than its factorization.

21982785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 497 counting only the distinct ones).

The product of its digits is 80640, while the sum is 42.

The square root of 21982785 is about 4688.5802755205. The cubic root of 21982785 is about 280.1308274680.

It can be divided in two parts, 219827 and 85, that added together give a palindrome (219912).

The spelling of 21982785 in words is "twenty-one million, nine hundred eighty-two thousand, seven hundred eighty-five".