221221210212120 has 64 divisors (see below), whose sum is σ = 663664692474720. Its totient is φ = 58992228337664.

The previous prime is 221221210212077. The next prime is 221221210212127. The reversal of 221221210212120 is 21212012122122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221210212127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106861594 + ... + 108912086.

Almost surely, 2^{221221210212120} is an apocalyptic number.

221221210212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221210212120 is an abundant number, since it is smaller than the sum of its proper divisors (442443482262600).

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

221221210212120 is a wasteful number, since it uses less digits than its factorization.

221221210212120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2949564 (or 2949560 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 221221210212120 its reverse (21212012122122), we get a palindrome (242433222334242).

The spelling of 221221210212120 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred ten million, two hundred twelve thousand, one hundred twenty".