21868043 has 2 divisors, whose sum is σ = 21868044. Its totient is φ = 21868042.

The previous prime is 21868039. The next prime is 21868081. The reversal of 21868043 is 34086812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21868043 - 2² = 21868039 is a prime.

It is a super-2 number, since 2×21868043² = 956422609299698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21868013) 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 as a sum of consecutive naturals, namely, 10934021 + 10934022.

It is an arithmetic number, because the mean of its divisors is an integer number (10934022).

Almost surely, 2^21868043 is an apocalyptic number.

21868043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21868043 is an equidigital number, since it uses as much as digits as its factorization.

21868043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21868043 is about 4676.3279397408. The cubic root of 21868043 is about 279.6425839235.

The spelling of 21868043 in words is "twenty-one million, eight hundred sixty-eight thousand, forty-three".