21221201212112 has 40 divisors (see below), whose sum is σ = 44859233393760. Its totient is φ = 9644854135680.

The previous prime is 21221201212109. The next prime is 21221201212117. The reversal of 21221201212112 is 21121210212212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221201212117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5679143 + ... + 8642630.

It is an arithmetic number, because the mean of its divisors is an integer number (1121480834844).

Almost surely, 2^{21221201212112} is an apocalyptic number.

21221201212112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21221201212112 is an abundant number, since it is smaller than the sum of its proper divisors (23638032181648).

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

21221201212112 is a wasteful number, since it uses less digits than its factorization.

21221201212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14330211 (or 14330205 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21221201212112 its reverse (21121210212212), we get a palindrome (42342411424324).

The spelling of 21221201212112 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, two hundred twelve thousand, one hundred twelve".