21221010002020 has 24 divisors (see below), whose sum is σ = 44570490330744. Its totient is φ = 8487190795776.

The previous prime is 21221010002011. The next prime is 21221010002053. The reversal of 21221010002020 is 2020001012212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 533358538596 + 20687651463424 = 730314^2 + 4548368^2 .

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, 75681877 + ... + 75961756.

It is an arithmetic number, because the mean of its divisors is an integer number (1857103763781).

Almost surely, 2^{21221010002020} is an apocalyptic number.

21221010002020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221010002020 is an abundant number, since it is smaller than the sum of its proper divisors (23349480328724).

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

21221010002020 is a wasteful number, since it uses less digits than its factorization.

21221010002020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151650639 (or 151650637 counting only the distinct ones).

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

Adding to 21221010002020 its reverse (2020001012212), we get a palindrome (23241011014232).

The spelling of 21221010002020 in words is "twenty-one trillion, two hundred twenty-one billion, ten million, two thousand, twenty".