16221871 has 2 divisors, whose sum is σ = 16221872. Its totient is φ = 16221870.

The previous prime is 16221857. The next prime is 16221889. The reversal of 16221871 is 17812261.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16221871 - 2⁷ = 16221743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16221971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8110935 + 8110936.

It is an arithmetic number, because the mean of its divisors is an integer number (8110936).

Almost surely, 2^16221871 is an apocalyptic number.

16221871 is a deficient number, since it is larger than the sum of its proper divisors (1).

16221871 is an equidigital number, since it uses as much as digits as its factorization.

16221871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 28.

The square root of 16221871 is about 4027.6383899253. The cubic root of 16221871 is about 253.1436170019.

The spelling of 16221871 in words is "sixteen million, two hundred twenty-one thousand, eight hundred seventy-one".