21211200012 has 96 divisors (see below), whose sum is σ = 53577422080. Its totient is φ = 6508512000.

The previous prime is 21211200011. The next prime is 21211200019. The reversal of 21211200012 is 21000211212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21211200011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9421887 + ... + 9424137.

Almost surely, 2^21211200012 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 21211200012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26788711040).

21211200012 is an abundant number, since it is smaller than the sum of its proper divisors (32366222068).

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

21211200012 is a wasteful number, since it uses less digits than its factorization.

21211200012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3431 (or 3429 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21211200012 its reverse (21000211212), we get a palindrome (42211411224).

It can be divided in two parts, 2121 and 1200012, that multiplied together give a palindrome (2545225452).

The spelling of 21211200012 in words is "twenty-one billion, two hundred eleven million, two hundred thousand, twelve".