1211431313 has 2 divisors, whose sum is σ = 1211431314. Its totient is φ = 1211431312.

The previous prime is 1211431301. The next prime is 1211431327. The reversal of 1211431313 is 3131341121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1044065344 + 167365969 = 32312^2 + 12937^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211431313 - 2⁸ = 1211431057 is a prime.

It is a super-3 number, since 3×1211431313³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1211431363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605715656 + 605715657.

It is an arithmetic number, because the mean of its divisors is an integer number (605715657).

Almost surely, 2^1211431313 is an apocalyptic number.

It is an amenable number.

1211431313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211431313 is an equidigital number, since it uses as much as digits as its factorization.

1211431313 is an evil number, because the sum of its binary digits is even.

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

The square root of 1211431313 is about 34805.6218591193. The cubic root of 1211431313 is about 1066.0222393388.

Adding to 1211431313 its reverse (3131341121), we get a palindrome (4342772434).

The spelling of 1211431313 in words is "one billion, two hundred eleven million, four hundred thirty-one thousand, three hundred thirteen".