21866998 has 16 divisors (see below), whose sum is σ = 34933680. Its totient is φ = 10230016.

The previous prime is 21866989. The next prime is 21867019. The reversal of 21866998 is 89966812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4290 + ... + 7882.

It is an arithmetic number, because the mean of its divisors is an integer number (2183355).

Almost surely, 2^21866998 is an apocalyptic number.

21866998 is a deficient number, since it is larger than the sum of its proper divisors (13066682).

21866998 is a wasteful number, since it uses less digits than its factorization.

21866998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3791.

The product of its digits is 373248, while the sum is 49.

The square root of 21866998 is about 4676.2162054379. The cubic root of 21866998 is about 279.6381294607.

The spelling of 21866998 in words is "twenty-one million, eight hundred sixty-six thousand, nine hundred ninety-eight".