21827986 has 8 divisors (see below), whose sum is σ = 32846220. Its totient is φ = 10879248.

The previous prime is 21827977. The next prime is 21828029. The reversal of 21827986 is 68972812.

It can be written as a sum of positive squares in 2 ways, for example, as 17480761 + 4347225 = 4181^2 + 2085^2 .

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

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, 16581 + ... + 17848.

Almost surely, 2^21827986 is an apocalyptic number.

21827986 is a deficient number, since it is larger than the sum of its proper divisors (11018234).

21827986 is a wasteful number, since it uses less digits than its factorization.

21827986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34748.

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

The square root of 21827986 is about 4672.0430220622. The cubic root of 21827986 is about 279.4717335564.

The spelling of 21827986 in words is "twenty-one million, eight hundred twenty-seven thousand, nine hundred eighty-six".