211872321 has 16 divisors (see below), whose sum is σ = 324011520. Its totient is φ = 136691280.

The previous prime is 211872319. The next prime is 211872329. The reversal of 211872321 is 123278112.

It is not a de Polignac number, because 211872321 - 2¹ = 211872319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (211872329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125730 + ... + 127403.

It is an arithmetic number, because the mean of its divisors is an integer number (20250720).

Almost surely, 2^211872321 is an apocalyptic number.

It is an amenable number.

211872321 is a deficient number, since it is larger than the sum of its proper divisors (112139199).

211872321 is a wasteful number, since it uses less digits than its factorization.

211872321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253173 (or 253167 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 211872321 is about 14555.8346033472. The cubic root of 211872321 is about 596.1534680163.

The spelling of 211872321 in words is "two hundred eleven million, eight hundred seventy-two thousand, three hundred twenty-one".