21100123123312 has 80 divisors (see below), whose sum is σ = 45213660872640. Its totient is φ = 9493995442176.

The previous prime is 21100123123273. The next prime is 21100123123319. The reversal of 21100123123312 is 21332132100112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100123123319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12172803 + ... + 13797730.

It is an arithmetic number, because the mean of its divisors is an integer number (565170760908).

Almost surely, 2^{21100123123312} is an apocalyptic number.

It is an amenable number.

21100123123312 is an abundant number, since it is smaller than the sum of its proper divisors (24113537749328).

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

21100123123312 is a wasteful number, since it uses less digits than its factorization.

21100123123312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25970690 (or 25970684 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21100123123312 its reverse (21332132100112), we get a palindrome (42432255223424).

The spelling of 21100123123312 in words is "twenty-one trillion, one hundred billion, one hundred twenty-three million, one hundred twenty-three thousand, three hundred twelve".