21226863 has 32 divisors (see below), whose sum is σ = 35195904. Its totient is φ = 11100672.

The previous prime is 21226853. The next prime is 21226879. The reversal of 21226863 is 36862212.

It is not a de Polignac number, because 21226863 - 2⁵ = 21226831 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21226863.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12406 + ... + 14012.

It is an arithmetic number, because the mean of its divisors is an integer number (1099872).

Almost surely, 2^21226863 is an apocalyptic number.

21226863 is a deficient number, since it is larger than the sum of its proper divisors (13969041).

21226863 is a wasteful number, since it uses less digits than its factorization.

21226863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671.

The product of its digits is 6912, while the sum is 30.

The square root of 21226863 is about 4607.2619851708. The cubic root of 21226863 is about 276.8823499994.

The spelling of 21226863 in words is "twenty-one million, two hundred twenty-six thousand, eight hundred sixty-three".