31143312221 has 16 divisors (see below), whose sum is σ = 36468569088. Its totient is φ = 26037398400.

The previous prime is 31143312203. The next prime is 31143312223. The reversal of 31143312221 is 12221334113.

It is a cyclic number.

It is not a de Polignac number, because 31143312221 - 2⁶ = 31143312157 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31143312223) 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, 1707476 + ... + 1725618.

It is an arithmetic number, because the mean of its divisors is an integer number (2279285568).

Almost surely, 2^31143312221 is an apocalyptic number.

It is an amenable number.

31143312221 is a deficient number, since it is larger than the sum of its proper divisors (5325256867).

31143312221 is a wasteful number, since it uses less digits than its factorization.

31143312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24172.

The product of its digits is 864, while the sum is 23.

Adding to 31143312221 its reverse (12221334113), we get a palindrome (43364646334).

The spelling of 31143312221 in words is "thirty-one billion, one hundred forty-three million, three hundred twelve thousand, two hundred twenty-one".