21986782 has 8 divisors (see below), whose sum is σ = 33006816. Its totient is φ = 10984512.

The previous prime is 21986777. The next prime is 21986807. The reversal of 21986782 is 28768912.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 723 + ... + 6670.

It is an arithmetic number, because the mean of its divisors is an integer number (4125852).

Almost surely, 2^21986782 is an apocalyptic number.

21986782 is a deficient number, since it is larger than the sum of its proper divisors (11020034).

21986782 is a wasteful number, since it uses less digits than its factorization.

21986782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8882.

The product of its digits is 96768, while the sum is 43.

The square root of 21986782 is about 4689.0065045807. The cubic root of 21986782 is about 280.1478046172.

The spelling of 21986782 in words is "twenty-one million, nine hundred eighty-six thousand, seven hundred eighty-two".