31233031221 has 16 divisors (see below), whose sum is σ = 47792332800. Its totient is φ = 17772768048.

The previous prime is 31233031211. The next prime is 31233031259. The reversal of 31233031221 is 12213033213.

It is not a de Polignac number, because 31233031221 - 2⁶ = 31233031157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31233031201) 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, 3106461 + ... + 3116498.

It is an arithmetic number, because the mean of its divisors is an integer number (2987020800).

Almost surely, 2^31233031221 is an apocalyptic number.

It is an amenable number.

31233031221 is a deficient number, since it is larger than the sum of its proper divisors (16559301579).

31233031221 is a wasteful number, since it uses less digits than its factorization.

31233031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6223208.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 31233031221 its reverse (12213033213), we get a palindrome (43446064434).

The spelling of 31233031221 in words is "thirty-one billion, two hundred thirty-three million, thirty-one thousand, two hundred twenty-one".