21001102210020 has 24 divisors (see below), whose sum is σ = 58803086188224. Its totient is φ = 5600293922656.

The previous prime is 21001102210013. The next prime is 21001102210037. The reversal of 21001102210020 is 2001220110012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21001102209978 and 21001102210005.

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, 175009185024 + ... + 175009185143.

It is an arithmetic number, because the mean of its divisors is an integer number (2450128591176).

Almost surely, 2^{21001102210020} is an apocalyptic number.

21001102210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001102210020 is an abundant number, since it is smaller than the sum of its proper divisors (37801983978204).

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

21001102210020 is a wasteful number, since it uses less digits than its factorization.

21001102210020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350018370179 (or 350018370177 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21001102210020 its reverse (2001220110012), we get a palindrome (23002322320032).

The spelling of 21001102210020 in words is "twenty-one trillion, one billion, one hundred two million, two hundred ten thousand, twenty".