21100000120 has 16 divisors (see below), whose sum is σ = 47475000360. Its totient is φ = 8440000032.

The previous prime is 21100000069. The next prime is 21100000123. The reversal of 21100000120 is 2100000112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100000123) 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, 263749962 + ... + 263750041.

Almost surely, 2^21100000120 is an apocalyptic number.

21100000120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100000120 is an abundant number, since it is smaller than the sum of its proper divisors (26375000240).

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

21100000120 is a wasteful number, since it uses less digits than its factorization.

21100000120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527500014 (or 527500010 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21100000120 its reverse (2100000112), we get a palindrome (23200000232).

The spelling of 21100000120 in words is "twenty-one billion, one hundred million, one hundred twenty", and thus it is an aban number.