212109305 has 16 divisors (see below), whose sum is σ = 260143488. Its totient is φ = 165984000.

The previous prime is 212109301. The next prime is 212109319. The reversal of 212109305 is 503901212.

It is not a de Polignac number, because 212109305 - 2² = 212109301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212109301) 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, 44225 + ... + 48785.

It is an arithmetic number, because the mean of its divisors is an integer number (16258968).

Almost surely, 2^212109305 is an apocalyptic number.

It is an amenable number.

212109305 is a deficient number, since it is larger than the sum of its proper divisors (48034183).

212109305 is a wasteful number, since it uses less digits than its factorization.

212109305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4768.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 212109305 is about 14563.9728439736. The cubic root of 212109305 is about 596.3756555913.

The spelling of 212109305 in words is "two hundred twelve million, one hundred nine thousand, three hundred five".