21227868 has 36 divisors (see below), whose sum is σ = 54221440. Its totient is φ = 7001856.

The previous prime is 21227867. The next prime is 21227887. The reversal of 21227868 is 86872212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227863) 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 11 ways as a sum of consecutive naturals, for example, 453 + ... + 6531.

Almost surely, 2^21227868 is an apocalyptic number.

It is an amenable number.

21227868 is an abundant number, since it is smaller than the sum of its proper divisors (32993572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21227868 is a wasteful number, since it uses less digits than its factorization.

21227868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6186 (or 6181 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 21227868 is about 4607.3710508271. The cubic root of 21227868 is about 276.8867196571.

The spelling of 21227868 in words is "twenty-one million, two hundred twenty-seven thousand, eight hundred sixty-eight".