212889305 has 16 divisors (see below), whose sum is σ = 262861200. Its totient is φ = 165399552.

The previous prime is 212889301. The next prime is 212889353. The reversal of 212889305 is 503988212.

It can be written as a sum of positive squares in 8 ways, for example, as 16581184 + 196308121 = 4072^2 + 14011^2 .

It is a cyclic number.

It is not a de Polignac number, because 212889305 - 2² = 212889301 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (212889301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193517 + ... + 194613.

It is an arithmetic number, because the mean of its divisors is an integer number (16428825).

Almost surely, 2^212889305 is an apocalyptic number.

It is an amenable number.

212889305 is a deficient number, since it is larger than the sum of its proper divisors (49971895).

212889305 is a wasteful number, since it uses less digits than its factorization.

212889305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 212889305 is about 14590.7266782707. The cubic root of 212889305 is about 597.1057885326.

The spelling of 212889305 in words is "two hundred twelve million, eight hundred eighty-nine thousand, three hundred five".