21000002112 has 112 divisors (see below), whose sum is σ = 61777676800. Its totient is φ = 6995289600.

The previous prime is 21000002083. The next prime is 21000002129. The reversal of 21000002112 is 21120000012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21000002094 and 21000002103.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3368214 + ... + 3374442.

It is an arithmetic number, because the mean of its divisors is an integer number (551586400).

Almost surely, 2^21000002112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000002112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30888838400).

21000002112 is an abundant number, since it is smaller than the sum of its proper divisors (40777674688).

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

21000002112 is a wasteful number, since it uses less digits than its factorization.

21000002112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8201 (or 8185 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21000002112 its reverse (21120000012), we get a palindrome (42120002124).

It can be divided in two parts, 210000021 and 12, that multiplied together give a palindrome (2520000252).

The spelling of 21000002112 in words is "twenty-one billion, two thousand, one hundred twelve".