21100130120 has 64 divisors (see below), whose sum is σ = 48665337840. Its totient is φ = 8228761600.

The previous prime is 21100130089. The next prime is 21100130123. The reversal of 21100130120 is 2103100112.

It can be written as a sum of positive squares in 8 ways, for example, as 5519598436 + 15580531684 = 74294^2 + 124822^2 .

It is not an unprimeable number, because it can be changed into a prime (21100130123) 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, 3232460 + ... + 3238980.

Almost surely, 2^21100130120 is an apocalyptic number.

21100130120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100130120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24332668920).

21100130120 is an abundant number, since it is smaller than the sum of its proper divisors (27565207720).

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

21100130120 is a wasteful number, since it uses less digits than its factorization.

21100130120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8546 (or 8542 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21100130120 its reverse (2103100112), we get a palindrome (23203230232).

The spelling of 21100130120 in words is "twenty-one billion, one hundred million, one hundred thirty thousand, one hundred twenty".