211773231 has 8 divisors (see below), whose sum is σ = 313738160. Its totient is φ = 141182136.

The previous prime is 211773203. The next prime is 211773239. The reversal of 211773231 is 132377112.

It is not a de Polignac number, because 211773231 - 2⁷ = 211773103 is a prime.

It is a super-2 number, since 2×211773231² = 89695802736358722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 7843453 = 211773231 / (2 + 1 + 1 + 7 + 7 + 3 + 2 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211773195 and 211773204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211773239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3921700 + ... + 3921753.

It is an arithmetic number, because the mean of its divisors is an integer number (39217270).

Almost surely, 2^211773231 is an apocalyptic number.

211773231 is a deficient number, since it is larger than the sum of its proper divisors (101964929).

211773231 is an equidigital number, since it uses as much as digits as its factorization.

211773231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7843462 (or 7843456 counting only the distinct ones).

The product of its digits is 1764, while the sum is 27.

The square root of 211773231 is about 14552.4304155698. The cubic root of 211773231 is about 596.0605157161.

The spelling of 211773231 in words is "two hundred eleven million, seven hundred seventy-three thousand, two hundred thirty-one".