21000112120 has 32 divisors (see below), whose sum is σ = 50884888320. Its totient is φ = 7753887360.

The previous prime is 21000112061. The next prime is 21000112127. The reversal of 21000112120 is 2121100012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21000112097 and 21000112106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000112127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20191896 + ... + 20192935.

It is an arithmetic number, because the mean of its divisors is an integer number (1590152760).

Almost surely, 2^21000112120 is an apocalyptic number.

21000112120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000112120 is an abundant number, since it is smaller than the sum of its proper divisors (29884776200).

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

21000112120 is a wasteful number, since it uses less digits than its factorization.

21000112120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40384855 (or 40384851 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000112120 its reverse (2121100012), we get a palindrome (23121212132).

The spelling of 21000112120 in words is "twenty-one billion, one hundred twelve thousand, one hundred twenty".