21821282 has 32 divisors (see below), whose sum is σ = 39294720. Its totient is φ = 8890560.

The previous prime is 21821263. The next prime is 21821309. The reversal of 21821282 is 28212812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28448 + ... + 29204.

It is an arithmetic number, because the mean of its divisors is an integer number (1227960).

Almost surely, 2^21821282 is an apocalyptic number.

21821282 is a deficient number, since it is larger than the sum of its proper divisors (17473438).

21821282 is a wasteful number, since it uses less digits than its factorization.

21821282 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866.

The product of its digits is 1024, while the sum is 26.

The square root of 21821282 is about 4671.3255078190. The cubic root of 21821282 is about 279.4431193675.

The spelling of 21821282 in words is "twenty-one million, eight hundred twenty-one thousand, two hundred eighty-two".