10111131221 has 4 divisors (see below), whose sum is σ = 10143027852. Its totient is φ = 10079234592.

The previous prime is 10111131203. The next prime is 10111131227. The reversal of 10111131221 is 12213111101.

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 4450224100 + 5660907121 = 66710^2 + 75239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10111131221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10111131196 and 10111131205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10111131227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15947840 + ... + 15948473.

It is an arithmetic number, because the mean of its divisors is an integer number (2535756963).

Almost surely, 2^10111131221 is an apocalyptic number.

It is an amenable number.

10111131221 is a deficient number, since it is larger than the sum of its proper divisors (31896631).

10111131221 is an equidigital number, since it uses as much as digits as its factorization.

10111131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31896630.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 10111131221 its reverse (12213111101), we get a palindrome (22324242322).

The spelling of 10111131221 in words is "ten billion, one hundred eleven million, one hundred thirty-one thousand, two hundred twenty-one".