21002220121000 has 128 divisors (see below), whose sum is σ = 52433316524160. Its totient is φ = 7846360704000.

The previous prime is 21002220120991. The next prime is 21002220121009. The reversal of 21002220121000 is 12102220012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21002220120991) and next prime (21002220121009).

It is not an unprimeable number, because it can be changed into a prime (21002220121009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2488362 + ... + 6942361.

It is an arithmetic number, because the mean of its divisors is an integer number (409635285345).

Almost surely, 2^{21002220121000} is an apocalyptic number.

21002220121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002220121000 is an abundant number, since it is smaller than the sum of its proper divisors (31431096403160).

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

21002220121000 is a wasteful number, since it uses less digits than its factorization.

21002220121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9430892 (or 9430878 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21002220121000 its reverse (12102220012), we get a palindrome (21014322341012).

The spelling of 21002220121000 in words is "twenty-one trillion, two billion, two hundred twenty million, one hundred twenty-one thousand".