211021231 has 2 divisors, whose sum is σ = 211021232. Its totient is φ = 211021230.

The previous prime is 211021199. The next prime is 211021241. The reversal of 211021231 is 132120112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211021231 - 2⁵ = 211021199 is a prime.

It is a super-2 number, since 2×211021231² = 89059919865510722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211021241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510615 + 105510616.

It is an arithmetic number, because the mean of its divisors is an integer number (105510616).

Almost surely, 2^211021231 is an apocalyptic number.

211021231 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021231 is an equidigital number, since it uses as much as digits as its factorization.

211021231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 211021231 is about 14526.5698291097. The cubic root of 211021231 is about 595.3541483220.

Adding to 211021231 its reverse (132120112), we get a palindrome (343141343).

The spelling of 211021231 in words is "two hundred eleven million, twenty-one thousand, two hundred thirty-one".