31121100113 has 4 divisors (see below), whose sum is σ = 31195022388. Its totient is φ = 31047177840.

The previous prime is 31121100091. The next prime is 31121100163. The reversal of 31121100113 is 31100112113.

It is a happy number.

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 4017404689 + 27103695424 = 63383^2 + 164632^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31121100113 is a prime.

It is a super-2 number, since 2×31121100113² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31121100163) 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, 36960506 + ... + 36961347.

It is an arithmetic number, because the mean of its divisors is an integer number (7798755597).

Almost surely, 2^31121100113 is an apocalyptic number.

It is an amenable number.

31121100113 is a deficient number, since it is larger than the sum of its proper divisors (73922275).

31121100113 is an equidigital number, since it uses as much as digits as its factorization.

31121100113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73922274.

The product of its (nonzero) digits is 18, while the sum is 14.

Adding to 31121100113 its reverse (31100112113), we get a palindrome (62221212226).

The spelling of 31121100113 in words is "thirty-one billion, one hundred twenty-one million, one hundred thousand, one hundred thirteen".