31101312221 has 16 divisors (see below), whose sum is σ = 36117504000. Its totient is φ = 26229918960.

The previous prime is 31101312217. The next prime is 31101312223. The reversal of 31101312221 is 12221310113.

It is not a de Polignac number, because 31101312221 - 2² = 31101312217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31101312221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31101312223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 185300 + ... + 310706.

It is an arithmetic number, because the mean of its divisors is an integer number (2257344000).

Almost surely, 2^31101312221 is an apocalyptic number.

It is an amenable number.

31101312221 is a deficient number, since it is larger than the sum of its proper divisors (5016191779).

31101312221 is a wasteful number, since it uses less digits than its factorization.

31101312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125984.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 31101312221 its reverse (12221310113), we get a palindrome (43322622334).

The spelling of 31101312221 in words is "thirty-one billion, one hundred one million, three hundred twelve thousand, two hundred twenty-one".