31143203221 has 36 divisors (see below), whose sum is σ = 35701243812. Its totient is φ = 27150619392.

The previous prime is 31143203219. The next prime is 31143203317. The reversal of 31143203221 is 12230234113.

It can be written as a sum of positive squares in 6 ways, for example, as 6459336900 + 24683866321 = 80370^2 + 157111^2 .

It is not a de Polignac number, because 31143203221 - 2¹ = 31143203219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31143203192 and 31143203201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31143203621) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 27880555 + ... + 27881671.

It is an arithmetic number, because the mean of its divisors is an integer number (991701217).

Almost surely, 2^31143203221 is an apocalyptic number.

It is an amenable number.

31143203221 is a deficient number, since it is larger than the sum of its proper divisors (4558040591).

31143203221 is a wasteful number, since it uses less digits than its factorization.

31143203221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1638 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 31143203221 its reverse (12230234113), we get a palindrome (43373437334).

The spelling of 31143203221 in words is "thirty-one billion, one hundred forty-three million, two hundred three thousand, two hundred twenty-one".