216171853 has 2 divisors, whose sum is σ = 216171854. Its totient is φ = 216171852.

The previous prime is 216171841. The next prime is 216171859. The reversal of 216171853 is 358171612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 172055689 + 44116164 = 13117^2 + 6642^2 .

It is a cyclic number.

It is not a de Polignac number, because 216171853 - 2²¹ = 214074701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216171859) 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, 108085926 + 108085927.

It is an arithmetic number, because the mean of its divisors is an integer number (108085927).

Almost surely, 2^216171853 is an apocalyptic number.

It is an amenable number.

216171853 is a deficient number, since it is larger than the sum of its proper divisors (1).

216171853 is an equidigital number, since it uses as much as digits as its factorization.

216171853 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 34.

The square root of 216171853 is about 14702.7838520465. The cubic root of 216171853 is about 600.1590809665.

The spelling of 216171853 in words is "two hundred sixteen million, one hundred seventy-one thousand, eight hundred fifty-three".