21826863 has 6 divisors (see below), whose sum is σ = 31527704. Its totient is φ = 14551236.

The previous prime is 21826859. The next prime is 21826867. The reversal of 21826863 is 36862812.

It is an interprime number because it is at equal distance from previous prime (21826859) and next prime (21826867).

It is not a de Polignac number, because 21826863 - 2² = 21826859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21826867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1212595 + ... + 1212612.

Almost surely, 2^21826863 is an apocalyptic number.

21826863 is a deficient number, since it is larger than the sum of its proper divisors (9700841).

21826863 is a wasteful number, since it uses less digits than its factorization.

21826863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2425213 (or 2425210 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21826863 is about 4671.9228375477. The cubic root of 21826863 is about 279.4669407468.

It can be divided in two parts, 2182 and 6863, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 21826863 in words is "twenty-one million, eight hundred twenty-six thousand, eight hundred sixty-three".