21200120012 has 24 divisors (see below), whose sum is σ = 37737781200. Its totient is φ = 10417980416.

The previous prime is 21200119961. The next prime is 21200120087. The reversal of 21200120012 is 21002100212.

It is a happy number.

21200120012 is a modest number, since divided by 120012 gives 212 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21200119975 and 21200120002.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1429628 + ... + 1444380.

It is an arithmetic number, because the mean of its divisors is an integer number (1572407550).

Almost surely, 2^21200120012 is an apocalyptic number.

It is an amenable number.

21200120012 is a deficient number, since it is larger than the sum of its proper divisors (16537661188).

21200120012 is a wasteful number, since it uses less digits than its factorization.

21200120012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20905 (or 20903 counting only the distinct ones).

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

Adding to 21200120012 its reverse (21002100212), we get a palindrome (42202220224).

The spelling of 21200120012 in words is "twenty-one billion, two hundred million, one hundred twenty thousand, twelve".