21031123113 has 96 divisors (see below), whose sum is σ = 43187219712. Its totient is φ = 9491558400.

The previous prime is 21031123097. The next prime is 21031123207. The reversal of 21031123113 is 31132113012.

It is not a de Polignac number, because 21031123113 - 2⁴ = 21031123097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21031123513) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 84493 + ... + 221813.

It is an arithmetic number, because the mean of its divisors is an integer number (449866872).

Almost surely, 2^21031123113 is an apocalyptic number.

It is an amenable number.

21031123113 is an abundant number, since it is smaller than the sum of its proper divisors (22156096599).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031123113 is a wasteful number, since it uses less digits than its factorization.

21031123113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137375 (or 137372 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21031123113 its reverse (31132113012), we get a palindrome (52163236125).

The spelling of 21031123113 in words is "twenty-one billion, thirty-one million, one hundred twenty-three thousand, one hundred thirteen".