21201211210212 has 216 divisors, whose sum is σ = 61040076552000. Its totient is φ = 6192693386880.

The previous prime is 21201211210189. The next prime is 21201211210217.

21201211210212 is a `hidden beast` number, since 2 + 120 + 121 + 1 + 210 + 212 = 666.

21201211210212 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21201211210217) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 75527983 + ... + 75808169.

It is an arithmetic number, because the mean of its divisors is an integer number (282592947000).

Almost surely, 2^{21201211210212} is an apocalyptic number.

21201211210212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201211210212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30520038276000).

21201211210212 is an abundant number, since it is smaller than the sum of its proper divisors (39838865341788).

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

21201211210212 is a wasteful number, since it uses less digits than its factorization.

21201211210212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280847 (or 280831 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

It can be divided in two parts, 2120121 and 1210212, that added together give a palindrome (3330333).

The spelling of 21201211210212 in words is "twenty-one trillion, two hundred one billion, two hundred eleven million, two hundred ten thousand, two hundred twelve".