211872309 has 32 divisors (see below), whose sum is σ = 333932544. Its totient is φ = 118030080.

The previous prime is 211872299. The next prime is 211872317. The reversal of 211872309 is 903278112.

It is not a de Polignac number, because 211872309 - 2⁵ = 211872277 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 211872309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211872319) 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 in 31 ways as a sum of consecutive naturals, for example, 19732 + ... + 28514.

It is an arithmetic number, because the mean of its divisors is an integer number (10435392).

Almost surely, 2^211872309 is an apocalyptic number.

It is an amenable number.

211872309 is a deficient number, since it is larger than the sum of its proper divisors (122060235).

211872309 is a wasteful number, since it uses less digits than its factorization.

211872309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8857.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 211872309 is about 14555.8341911414. The cubic root of 211872309 is about 596.1534567613.

The spelling of 211872309 in words is "two hundred eleven million, eight hundred seventy-two thousand, three hundred nine".