21989286 has 32 divisors (see below), whose sum is σ = 53308800. Its totient is φ = 6663240.

The previous prime is 21989281. The next prime is 21989291. The reversal of 21989286 is 68298912.

It is an interprime number because it is at equal distance from previous prime (21989281) and next prime (21989291).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21989281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17916 + ... + 19103.

It is an arithmetic number, because the mean of its divisors is an integer number (1665900).

Almost surely, 2^21989286 is an apocalyptic number.

21989286 is an abundant number, since it is smaller than the sum of its proper divisors (31319514).

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

21989286 is a wasteful number, since it uses less digits than its factorization.

21989286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37041 (or 37035 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 21989286 is about 4689.2735044994. The cubic root of 21989286 is about 280.1584392411.

The spelling of 21989286 in words is "twenty-one million, nine hundred eighty-nine thousand, two hundred eighty-six".