1211206331 has 2 divisors, whose sum is σ = 1211206332. Its totient is φ = 1211206330.

The previous prime is 1211206307. The next prime is 1211206333. The reversal of 1211206331 is 1336021121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211206331 - 2⁶ = 1211206267 is a prime.

It is a super-2 number, since 2×1211206331² = 2934041552508963122, which contains 22 as substring.

Together with 1211206333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1211206333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605603165 + 605603166.

It is an arithmetic number, because the mean of its divisors is an integer number (605603166).

Almost surely, 2^1211206331 is an apocalyptic number.

1211206331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211206331 is an equidigital number, since it uses as much as digits as its factorization.

1211206331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1211206331 is about 34802.3897311665. The cubic root of 1211206331 is about 1065.9562428432.

Adding to 1211206331 its reverse (1336021121), we get a palindrome (2547227452).

The spelling of 1211206331 in words is "one billion, two hundred eleven million, two hundred six thousand, three hundred thirty-one".