21001120122220 has 48 divisors (see below), whose sum is σ = 50405984935488. Its totient is φ = 7199913093120.

The previous prime is 21001120122197. The next prime is 21001120122251. The reversal of 21001120122220 is 2222102110012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21001120122194 and 21001120122203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2754241 + ... + 7041880.

It is an arithmetic number, because the mean of its divisors is an integer number (1050124686156).

Almost surely, 2^{21001120122220} is an apocalyptic number.

21001120122220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001120122220 is an abundant number, since it is smaller than the sum of its proper divisors (29404864813268).

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

21001120122220 is a wasteful number, since it uses less digits than its factorization.

21001120122220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9811450 (or 9811448 counting only the distinct ones).

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

Adding to 21001120122220 its reverse (2222102110012), we get a palindrome (23223222232232).

The spelling of 21001120122220 in words is "twenty-one trillion, one billion, one hundred twenty million, one hundred twenty-two thousand, two hundred twenty".