21121021201212 has 72 divisors (see below), whose sum is σ = 56543332468896. Its totient is φ = 6624615573504.

The previous prime is 21121021201207. The next prime is 21121021201321. The reversal of 21121021201212 is 21210212012112.

21121021201212 is a `hidden beast` number, since 21 + 1 + 210 + 21 + 201 + 212 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1574808 + ... + 6687455.

It is an arithmetic number, because the mean of its divisors is an integer number (785324062068).

Almost surely, 2^{21121021201212} is an apocalyptic number.

It is an amenable number.

21121021201212 is an abundant number, since it is smaller than the sum of its proper divisors (35422311267684).

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

21121021201212 is a wasteful number, since it uses less digits than its factorization.

21121021201212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8266467 (or 8266462 counting only the distinct ones).

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

Adding to 21121021201212 its reverse (21210212012112), we get a palindrome (42331233213324).

The spelling of 21121021201212 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, two hundred one thousand, two hundred twelve".