31431311 has 2 divisors, whose sum is σ = 31431312. Its totient is φ = 31431310.

The previous prime is 31431307. The next prime is 31431319. The reversal of 31431311 is 11313413.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31431311 - 2² = 31431307 is a prime.

It is a super-2 number, since 2×31431311² = 1975854622357442, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31431311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31431319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715655 + 15715656.

It is an arithmetic number, because the mean of its divisors is an integer number (15715656).

Almost surely, 2^31431311 is an apocalyptic number.

31431311 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431311 is an equidigital number, since it uses as much as digits as its factorization.

31431311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 17.

The square root of 31431311 is about 5606.3634380943. The cubic root of 31431311 is about 315.5882549256.

Adding to 31431311 its reverse (11313413), we get a palindrome (42744724).

The spelling of 31431311 in words is "thirty-one million, four hundred thirty-one thousand, three hundred eleven".