21022986 has 8 divisors (see below), whose sum is σ = 42045984. Its totient is φ = 7007660.

The previous prime is 21022921. The next prime is 21022997. The reversal of 21022986 is 68922012.

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

21022986 is an admirable number.

It is a Curzon 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, 1751910 + ... + 1751921.

It is an arithmetic number, because the mean of its divisors is an integer number (5255748).

Almost surely, 2^21022986 is an apocalyptic number.

21022986 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21022986 is a wasteful number, since it uses less digits than its factorization.

21022986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3503836.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 21022986 is about 4585.0829872533. The cubic root of 21022986 is about 275.9930422527.

Adding to 21022986 its reverse (68922012), we get a palindrome (89944998).

The spelling of 21022986 in words is "twenty-one million, twenty-two thousand, nine hundred eighty-six".