31213543 has 2 divisors, whose sum is σ = 31213544. Its totient is φ = 31213542.

The previous prime is 31213531. The next prime is 31213549. The reversal of 31213543 is 34531213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31213543 - 2¹³ = 31205351 is a prime.

It is a super-2 number, since 2×31213543² = 1948570533225698, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31213549) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606771 + 15606772.

It is an arithmetic number, because the mean of its divisors is an integer number (15606772).

Almost surely, 2^31213543 is an apocalyptic number.

31213543 is a deficient number, since it is larger than the sum of its proper divisors (1).

31213543 is an equidigital number, since it uses as much as digits as its factorization.

31213543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 22.

The square root of 31213543 is about 5586.9081789484. The cubic root of 31213543 is about 314.8577269658.

Adding to 31213543 its reverse (34531213), we get a palindrome (65744756).

The spelling of 31213543 in words is "thirty-one million, two hundred thirteen thousand, five hundred forty-three".