31011212321 has 4 divisors (see below), whose sum is σ = 32080564500. Its totient is φ = 29941860144.

The previous prime is 31011212257. The next prime is 31011212341. The reversal of 31011212321 is 12321211013.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18786814225 + 12224398096 = 137065^2 + 110564^2 .

It is not a de Polignac number, because 31011212321 - 2⁶ = 31011212257 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 31011212321.

It is not an unprimeable number, because it can be changed into a prime (31011212341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 534676046 + ... + 534676103.

It is an arithmetic number, because the mean of its divisors is an integer number (8020141125).

Almost surely, 2^31011212321 is an apocalyptic number.

It is an amenable number.

31011212321 is a deficient number, since it is larger than the sum of its proper divisors (1069352179).

31011212321 is a wasteful number, since it uses less digits than its factorization.

31011212321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069352178.

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

Adding to 31011212321 its reverse (12321211013), we get a palindrome (43332423334).

The spelling of 31011212321 in words is "thirty-one billion, eleven million, two hundred twelve thousand, three hundred twenty-one".