21002021122220 has 36 divisors (see below), whose sum is σ = 46105193084160. Its totient is φ = 8035555903584.

The previous prime is 21002021122217. The next prime is 21002021122253. The reversal of 21002021122220 is 2222112020012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 992523500 + ... + 992544659.

Almost surely, 2^{21002021122220} is an apocalyptic number.

21002021122220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002021122220 is an abundant number, since it is smaller than the sum of its proper divisors (25103171961940).

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

21002021122220 is a wasteful number, since it uses less digits than its factorization.

21002021122220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1985068214 (or 1985068189 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21002021122220 its reverse (2222112020012), we get a palindrome (23224133142232).

The spelling of 21002021122220 in words is "twenty-one trillion, two billion, twenty-one million, one hundred twenty-two thousand, two hundred twenty".