31221213543 has 12 divisors (see below), whose sum is σ = 48566332360. Its totient is φ = 19213054416.

The previous prime is 31221213503. The next prime is 31221213547. The reversal of 31221213543 is 34531212213.

31221213543 is a `hidden beast` number, since 312 + 212 + 135 + 4 + 3 = 666.

It is not a de Polignac number, because 31221213543 - 2²⁰ = 31220164967 is a prime.

It is a super-2 number, since 2×31221213543² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221213547) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133423873 + ... + 133424106.

Almost surely, 2^31221213543 is an apocalyptic number.

31221213543 is a deficient number, since it is larger than the sum of its proper divisors (17345118817).

31221213543 is a wasteful number, since it uses less digits than its factorization.

31221213543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266847998 (or 266847995 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

Adding to 31221213543 its reverse (34531212213), we get a palindrome (65752425756).

The spelling of 31221213543 in words is "thirty-one billion, two hundred twenty-one million, two hundred thirteen thousand, five hundred forty-three".