21864806 has 8 divisors (see below), whose sum is σ = 32817504. Its totient is φ = 10925640.

The previous prime is 21864797. The next prime is 21864853. The reversal of 21864806 is 60846812.

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

It is a Curzon number.

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, 3296 + ... + 7388.

It is an arithmetic number, because the mean of its divisors is an integer number (4102188).

Almost surely, 2^21864806 is an apocalyptic number.

21864806 is a deficient number, since it is larger than the sum of its proper divisors (10952698).

21864806 is a wasteful number, since it uses less digits than its factorization.

21864806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6766.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 21864806 is about 4675.9818220348. The cubic root of 21864806 is about 279.6287852842.

The spelling of 21864806 in words is "twenty-one million, eight hundred sixty-four thousand, eight hundred six".