31221224643 has 16 divisors (see below), whose sum is σ = 47577680640. Its totient is φ = 17839769376.

The previous prime is 31221224633. The next prime is 31221224677. The reversal of 31221224643 is 34642212213.

It is not a de Polignac number, because 31221224643 - 2⁵ = 31221224611 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31221224643.

It is not an unprimeable number, because it can be changed into a prime (31221224633) 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 in 15 ways as a sum of consecutive naturals, for example, 708121 + ... + 750917.

It is an arithmetic number, because the mean of its divisors is an integer number (2973605040).

Almost surely, 2^31221224643 is an apocalyptic number.

31221224643 is a deficient number, since it is larger than the sum of its proper divisors (16356455997).

31221224643 is a wasteful number, since it uses less digits than its factorization.

31221224643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77546.

The product of its digits is 13824, while the sum is 30.

Adding to 31221224643 its reverse (34642212213), we get a palindrome (65863436856).

The spelling of 31221224643 in words is "thirty-one billion, two hundred twenty-one million, two hundred twenty-four thousand, six hundred forty-three".