21102121120 has 24 divisors (see below), whose sum is σ = 49853761524. Its totient is φ = 8440848384.

The previous prime is 21102121093. The next prime is 21102121123. The reversal of 21102121120 is 2112120112.

It can be written as a sum of positive squares in 2 ways, for example, as 20928830224 + 173290896 = 144668^2 + 13164^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21102121120.

It is not an unprimeable number, because it can be changed into a prime (21102121123) 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, 65943969 + ... + 65944288.

Almost surely, 2^21102121120 is an apocalyptic number.

21102121120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102121120 is an abundant number, since it is smaller than the sum of its proper divisors (28751640404).

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

21102121120 is a wasteful number, since it uses less digits than its factorization.

21102121120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131888272 (or 131888264 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21102121120 its reverse (2112120112), we get a palindrome (23214241232).

The spelling of 21102121120 in words is "twenty-one billion, one hundred two million, one hundred twenty-one thousand, one hundred twenty".