21866063 has 4 divisors (see below), whose sum is σ = 23152320. Its totient is φ = 20579808.

The previous prime is 21866057. The next prime is 21866069. The reversal of 21866063 is 36066812.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21866057) and next prime (21866069).

It is a cyclic number.

It is not a de Polignac number, because 21866063 - 2⁸ = 21865807 is a prime.

It is a super-2 number, since 2×21866063² = 956249422239938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21866069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 643103 + ... + 643136.

It is an arithmetic number, because the mean of its divisors is an integer number (5788080).

Almost surely, 2^21866063 is an apocalyptic number.

21866063 is a deficient number, since it is larger than the sum of its proper divisors (1286257).

21866063 is a wasteful number, since it uses less digits than its factorization.

21866063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286256.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 21866063 is about 4676.1162303775. The cubic root of 21866063 is about 279.6341437683.

The spelling of 21866063 in words is "twenty-one million, eight hundred sixty-six thousand, sixty-three".