21226872 has 16 divisors (see below), whose sum is σ = 53067240. Its totient is φ = 7075616.

The previous prime is 21226853. The next prime is 21226879. The reversal of 21226872 is 27862212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226879) 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 3 ways as a sum of consecutive naturals, for example, 442203 + ... + 442250.

Almost surely, 2^21226872 is an apocalyptic number.

It is an amenable number.

21226872 is an abundant number, since it is smaller than the sum of its proper divisors (31840368).

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

21226872 is a wasteful number, since it uses less digits than its factorization.

21226872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884462 (or 884458 counting only the distinct ones).

The product of its digits is 5376, while the sum is 30.

The square root of 21226872 is about 4607.2629618896. The cubic root of 21226872 is about 276.8823891313.

The spelling of 21226872 in words is "twenty-one million, two hundred twenty-six thousand, eight hundred seventy-two".