21850771 has 2 divisors, whose sum is σ = 21850772. Its totient is φ = 21850770.

The previous prime is 21850769. The next prime is 21850783. The reversal of 21850771 is 17705812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21850771 - 2¹ = 21850769 is a prime.

Together with 21850769, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21850721) 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 as a sum of consecutive naturals, namely, 10925385 + 10925386.

It is an arithmetic number, because the mean of its divisors is an integer number (10925386).

Almost surely, 2^21850771 is an apocalyptic number.

21850771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21850771 is an equidigital number, since it uses as much as digits as its factorization.

21850771 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 21850771 is about 4674.4808267871. The cubic root of 21850771 is about 279.5689413196.

The spelling of 21850771 in words is "twenty-one million, eight hundred fifty thousand, seven hundred seventy-one".