21221001110020 has 24 divisors (see below), whose sum is σ = 44567471554200. Its totient is φ = 8487758687232.

The previous prime is 21221001110009. The next prime is 21221001110069. The reversal of 21221001110020 is 2001110012212.

It can be written as a sum of positive squares in 4 ways, for example, as 15501795821824 + 5719205288196 = 3937232^2 + 2391486^2 .

It is a super-2 number, since 2×21221001110020² (a number of 27 digits) contains 22 as substring.

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, 39838605 + ... + 40367764.

It is an arithmetic number, because the mean of its divisors is an integer number (1856977981425).

Almost surely, 2^{21221001110020} is an apocalyptic number.

21221001110020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221001110020 is an abundant number, since it is smaller than the sum of its proper divisors (23346470444180).

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

21221001110020 is a wasteful number, since it uses less digits than its factorization.

21221001110020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80219607 (or 80219605 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21221001110020 its reverse (2001110012212), we get a palindrome (23222111122232).

The spelling of 21221001110020 in words is "twenty-one trillion, two hundred twenty-one billion, one million, one hundred ten thousand, twenty".