21863879 has 2 divisors, whose sum is σ = 21863880. Its totient is φ = 21863878.

The previous prime is 21863867. The next prime is 21863893. The reversal of 21863879 is 97836812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21863879 - 2²⁰ = 20815303 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21863899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10931939 + 10931940.

It is an arithmetic number, because the mean of its divisors is an integer number (10931940).

Almost surely, 2^21863879 is an apocalyptic number.

21863879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21863879 is an equidigital number, since it uses as much as digits as its factorization.

21863879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 21863879 is about 4675.8826974166. The cubic root of 21863879 is about 279.6248334305.

The spelling of 21863879 in words is "twenty-one million, eight hundred sixty-three thousand, eight hundred seventy-nine".