21221221000120 has 16 divisors (see below), whose sum is σ = 47747747250360. Its totient is φ = 8488488400032.

The previous prime is 21221221000087. The next prime is 21221221000121. The reversal of 21221221000120 is 2100012212212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21221221000094 and 21221221000103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221221000121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265265262462 + ... + 265265262541.

Almost surely, 2^{21221221000120} is an apocalyptic number.

21221221000120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221221000120 is an abundant number, since it is smaller than the sum of its proper divisors (26526526250240).

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

21221221000120 is a wasteful number, since it uses less digits than its factorization.

21221221000120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530530525014 (or 530530525010 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221221000120 its reverse (2100012212212), we get a palindrome (23321233212332).

The spelling of 21221221000120 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty", and thus it is an aban number.