21000122012 has 12 divisors (see below), whose sum is σ = 36784793136. Its totient is φ = 10490181120.

The previous prime is 21000121997. The next prime is 21000122027. The reversal of 21000122012 is 21022100012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21000121997) and next prime (21000122027).

It is a junction number, because it is equal to n+sod(n) for n = 21000121984 and 21000122002.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2465189 + ... + 2473692.

It is an arithmetic number, because the mean of its divisors is an integer number (3065399428).

Almost surely, 2^21000122012 is an apocalyptic number.

It is an amenable number.

21000122012 is a deficient number, since it is larger than the sum of its proper divisors (15784671124).

21000122012 is a wasteful number, since it uses less digits than its factorization.

21000122012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4939948 (or 4939946 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21000122012 its reverse (21022100012), we get a palindrome (42022222024).

The spelling of 21000122012 in words is "twenty-one billion, one hundred twenty-two thousand, twelve".