31113012221 has 4 divisors (see below), whose sum is σ = 32750539200. Its totient is φ = 29475485244.

The previous prime is 31113012209. The next prime is 31113012233. The reversal of 31113012221 is 12221031113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (31113012209) and next prime (31113012233).

It is a cyclic number.

It is not a de Polignac number, because 31113012221 - 2¹⁰ = 31113011197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31113012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31113012421) 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, 818763461 + ... + 818763498.

It is an arithmetic number, because the mean of its divisors is an integer number (8187634800).

Almost surely, 2^31113012221 is an apocalyptic number.

It is an amenable number.

31113012221 is a deficient number, since it is larger than the sum of its proper divisors (1637526979).

31113012221 is a wasteful number, since it uses less digits than its factorization.

31113012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637526978.

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

Adding to 31113012221 its reverse (12221031113), we get a palindrome (43334043334).

The spelling of 31113012221 in words is "thirty-one billion, one hundred thirteen million, twelve thousand, two hundred twenty-one".