21225863 has 2 divisors, whose sum is σ = 21225864. Its totient is φ = 21225862.

The previous prime is 21225851. The next prime is 21225881. The reversal of 21225863 is 36852212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21225863 - 2²² = 17031559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21225833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612931 + 10612932.

It is an arithmetic number, because the mean of its divisors is an integer number (10612932).

Almost surely, 2^21225863 is an apocalyptic number.

21225863 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225863 is an equidigital number, since it uses as much as digits as its factorization.

21225863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 21225863 is about 4607.1534595670. The cubic root of 21225863 is about 276.8780019445.

The spelling of 21225863 in words is "twenty-one million, two hundred twenty-five thousand, eight hundred sixty-three".