21424776 has 64 divisors (see below), whose sum is σ = 57456000. Its totient is φ = 6640128.

The previous prime is 21424763. The next prime is 21424787. The reversal of 21424776 is 67742412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19900 + ... + 20948.

It is an arithmetic number, because the mean of its divisors is an integer number (897750).

Almost surely, 2^21424776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21424776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28728000).

21424776 is an abundant number, since it is smaller than the sum of its proper divisors (36031224).

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

21424776 is a wasteful number, since it uses less digits than its factorization.

21424776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118 (or 1114 counting only the distinct ones).

The product of its digits is 18816, while the sum is 33.

The square root of 21424776 is about 4628.6905275682. The cubic root of 21424776 is about 277.7402124253.

The spelling of 21424776 in words is "twenty-one million, four hundred twenty-four thousand, seven hundred seventy-six".