21021122210020 has 24 divisors (see below), whose sum is σ = 44868034621368. Its totient is φ = 8270605459200.

The previous prime is 21021122209993. The next prime is 21021122210041. The reversal of 21021122210020 is 2001222112012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2450176612416 + 18570945597604 = 1565304^2 + 4309402^2 .

It is a super-2 number, since 2×21021122210020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21021122209976 and 21021122210003.

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, 8615212801 + ... + 8615215240.

It is an arithmetic number, because the mean of its divisors is an integer number (1869501442557).

Almost surely, 2^{21021122210020} is an apocalyptic number.

21021122210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021122210020 is an abundant number, since it is smaller than the sum of its proper divisors (23846912411348).

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

21021122210020 is a wasteful number, since it uses less digits than its factorization.

21021122210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17230428111 (or 17230428109 counting only the distinct ones).

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

Adding to 21021122210020 its reverse (2001222112012), we get a palindrome (23022344322032).

The spelling of 21021122210020 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-two million, two hundred ten thousand, twenty".