21852851 has 2 divisors, whose sum is σ = 21852852. Its totient is φ = 21852850.

The previous prime is 21852827. The next prime is 21852881. The reversal of 21852851 is 15825812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21852851 - 2¹⁴ = 21836467 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21852881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10926425 + 10926426.

It is an arithmetic number, because the mean of its divisors is an integer number (10926426).

Almost surely, 2^21852851 is an apocalyptic number.

21852851 is a deficient number, since it is larger than the sum of its proper divisors (1).

21852851 is an equidigital number, since it uses as much as digits as its factorization.

21852851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6400, while the sum is 32.

The square root of 21852851 is about 4674.7033060933. The cubic root of 21852851 is about 279.5778118677.

The spelling of 21852851 in words is "twenty-one million, eight hundred fifty-two thousand, eight hundred fifty-one".