21101210220020 has 96 divisors (see below), whose sum is σ = 53435550873600. Its totient is φ = 6837568746624.

The previous prime is 21101210219927. The next prime is 21101210220061. The reversal of 21101210220020 is 2002201210112.

It is a super-2 number, since 2×21101210220020² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21101210219977 and 21101210220004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8351792 + ... + 10580871.

It is an arithmetic number, because the mean of its divisors is an integer number (556620321600).

Almost surely, 2^{21101210220020} is an apocalyptic number.

21101210220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101210220020 is an abundant number, since it is smaller than the sum of its proper divisors (32334340653580).

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

21101210220020 is a wasteful number, since it uses less digits than its factorization.

21101210220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18933117 (or 18933115 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21101210220020 its reverse (2002201210112), we get a palindrome (23103411430132).

The spelling of 21101210220020 in words is "twenty-one trillion, one hundred one billion, two hundred ten million, two hundred twenty thousand, twenty".