212166305 has 16 divisors (see below), whose sum is σ = 275380560. Its totient is φ = 155993088.

The previous prime is 212166277. The next prime is 212166323. The reversal of 212166305 is 503661212.

It can be written as a sum of positive squares in 8 ways, for example, as 15241216 + 196925089 = 3904^2 + 14033^2 .

It is a cyclic number.

It is not a de Polignac number, because 212166305 - 2¹⁰ = 212165281 is a prime.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 8141 + ... + 22149.

It is an arithmetic number, because the mean of its divisors is an integer number (17211285).

Almost surely, 2^212166305 is an apocalyptic number.

It is an amenable number.

212166305 is a deficient number, since it is larger than the sum of its proper divisors (63214255).

212166305 is a wasteful number, since it uses less digits than its factorization.

212166305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14260.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 212166305 is about 14565.9295961501. The cubic root of 212166305 is about 596.4290720249.

The spelling of 212166305 in words is "two hundred twelve million, one hundred sixty-six thousand, three hundred five".