811211431 has 2 divisors, whose sum is σ = 811211432. Its totient is φ = 811211430.

The previous prime is 811211419. The next prime is 811211437. The reversal of 811211431 is 134112118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 811211431 - 2⁹ = 811210919 is a prime.

It is a super-2 number, since 2×811211431² = 1316127971570135522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (811211437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405605715 + 405605716.

It is an arithmetic number, because the mean of its divisors is an integer number (405605716).

Almost surely, 2^811211431 is an apocalyptic number.

811211431 is a deficient number, since it is larger than the sum of its proper divisors (1).

811211431 is an equidigital number, since it uses as much as digits as its factorization.

811211431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 22.

The square root of 811211431 is about 28481.7736631692. The cubic root of 811211431 is about 932.6342360787.

Adding to 811211431 its reverse (134112118), we get a palindrome (945323549).

The spelling of 811211431 in words is "eight hundred eleven million, two hundred eleven thousand, four hundred thirty-one".