21011031113 has 4 divisors (see below), whose sum is σ = 21355474308. Its totient is φ = 20666587920.

The previous prime is 21011031103. The next prime is 21011031149. The reversal of 21011031113 is 31113011012.

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 7575439369 + 13435591744 = 87037^2 + 115912^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011031113 - 2³⁰ = 19937289289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011031103) 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, 172221506 + ... + 172221627.

It is an arithmetic number, because the mean of its divisors is an integer number (5338868577).

Almost surely, 2^21011031113 is an apocalyptic number.

It is an amenable number.

21011031113 is a deficient number, since it is larger than the sum of its proper divisors (344443195).

21011031113 is an equidigital number, since it uses as much as digits as its factorization.

21011031113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344443194.

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

Adding to 21011031113 its reverse (31113011012), we get a palindrome (52124042125).

The spelling of 21011031113 in words is "twenty-one billion, eleven million, thirty-one thousand, one hundred thirteen".