21101011010020 has 24 divisors (see below), whose sum is σ = 44313066766584. Its totient is φ = 8440224662016.

The previous prime is 21101011010011. The next prime is 21101011010033. The reversal of 21101011010020 is 2001011010112.

It can be written as a sum of positive squares in 4 ways, for example, as 863591055616 + 20237419954404 = 929296^2 + 4498602^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21101011009979 and 21101011010006.

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, 10269207 + ... + 12151486.

It is an arithmetic number, because the mean of its divisors is an integer number (1846377781941).

Almost surely, 2^{21101011010020} is an apocalyptic number.

21101011010020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101011010020 is an abundant number, since it is smaller than the sum of its proper divisors (23212055756564).

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

21101011010020 is a wasteful number, since it uses less digits than its factorization.

21101011010020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22467759 (or 22467757 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21101011010020 its reverse (2001011010112), we get a palindrome (23102022020132).

The spelling of 21101011010020 in words is "twenty-one trillion, one hundred one billion, eleven million, ten thousand, twenty".