31111013221 has 4 divisors (see below), whose sum is σ = 31334833600. Its totient is φ = 30887192844.

The previous prime is 31111013207. The next prime is 31111013243. The reversal of 31111013221 is 12231011113.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31111013221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31111013195 and 31111013204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31111013261) 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, 111909981 + ... + 111910258.

It is an arithmetic number, because the mean of its divisors is an integer number (7833708400).

Almost surely, 2^31111013221 is an apocalyptic number.

It is an amenable number.

31111013221 is a deficient number, since it is larger than the sum of its proper divisors (223820379).

31111013221 is a wasteful number, since it uses less digits than its factorization.

31111013221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223820378.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 31111013221 its reverse (12231011113), we get a palindrome (43342024334).

The spelling of 31111013221 in words is "thirty-one billion, one hundred eleven million, thirteen thousand, two hundred twenty-one".