21126121116 has 96 divisors (see below), whose sum is σ = 50553484800. Its totient is φ = 6865171200.

The previous prime is 21126121097. The next prime is 21126121129. The reversal of 21126121116 is 61112162112.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28587075 + ... + 28587813.

It is an arithmetic number, because the mean of its divisors is an integer number (526598800).

Almost surely, 2^21126121116 is an apocalyptic number.

It is an amenable number.

21126121116 is an abundant number, since it is smaller than the sum of its proper divisors (29427363684).

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

21126121116 is a wasteful number, since it uses less digits than its factorization.

21126121116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179 (or 1177 counting only the distinct ones).

The product of its digits is 288, while the sum is 24.

Adding to 21126121116 its reverse (61112162112), we get a palindrome (82238283228).

The spelling of 21126121116 in words is "twenty-one billion, one hundred twenty-six million, one hundred twenty-one thousand, one hundred sixteen".