21824851 has 2 divisors, whose sum is σ = 21824852. Its totient is φ = 21824850.

The previous prime is 21824843. The next prime is 21824879. The reversal of 21824851 is 15842812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21824851 - 2³ = 21824843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21824801) by changing a digit.

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 as a sum of consecutive naturals, namely, 10912425 + 10912426.

It is an arithmetic number, because the mean of its divisors is an integer number (10912426).

Almost surely, 2^21824851 is an apocalyptic number.

21824851 is a deficient number, since it is larger than the sum of its proper divisors (1).

21824851 is an equidigital number, since it uses as much as digits as its factorization.

21824851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5120, while the sum is 31.

The square root of 21824851 is about 4671.7075036864. The cubic root of 21824851 is about 279.4583533964.

The spelling of 21824851 in words is "twenty-one million, eight hundred twenty-four thousand, eight hundred fifty-one".