21001202101020 has 48 divisors (see below), whose sum is σ = 58806373788288. Its totient is φ = 5600034093120.

The previous prime is 21001202100947. The next prime is 21001202101027. The reversal of 21001202101020 is 2010120210012.

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 = 21001202100987 and 21001202101005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001202101027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7768054 + ... + 10116573.

It is an arithmetic number, because the mean of its divisors is an integer number (1225132787256).

Almost surely, 2^{21001202101020} is an apocalyptic number.

21001202101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001202101020 is an abundant number, since it is smaller than the sum of its proper divisors (37805171687268).

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

21001202101020 is a wasteful number, since it uses less digits than its factorization.

21001202101020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17904210 (or 17904208 counting only the distinct ones).

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

Adding to 21001202101020 its reverse (2010120210012), we get a palindrome (23011322311032).

The spelling of 21001202101020 in words is "twenty-one trillion, one billion, two hundred two million, one hundred one thousand, twenty".