21010021020220 has 24 divisors (see below), whose sum is σ = 44349650596944. Its totient is φ = 8360464321536.

The previous prime is 21010021020217. The next prime is 21010021020319. The reversal of 21010021020220 is 2202012001012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21010021020220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2721501454 + ... + 2721509173.

It is an arithmetic number, because the mean of its divisors is an integer number (1847902108206).

Almost surely, 2^{21010021020220} is an apocalyptic number.

21010021020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010021020220 is an abundant number, since it is smaller than the sum of its proper divisors (23339629576724).

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

21010021020220 is a wasteful number, since it uses less digits than its factorization.

21010021020220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5443010829 (or 5443010827 counting only the distinct ones).

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

Adding to 21010021020220 its reverse (2202012001012), we get a palindrome (23212033021232).

The spelling of 21010021020220 in words is "twenty-one trillion, ten billion, twenty-one million, twenty thousand, two hundred twenty".