21202100121020 has 384 divisors, whose sum is σ = 59069051338752. Its totient is φ = 6201855590400.

The previous prime is 21202100120987. The next prime is 21202100121053. The reversal of 21202100121020 is 2012100120212.

It is an interprime number because it is at equal distance from previous prime (21202100120987) and next prime (21202100121053).

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 = 21202100120986 and 21202100121004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1213550885 + ... + 1213568355.

It is an arithmetic number, because the mean of its divisors is an integer number (153825654528).

Almost surely, 2^{21202100121020} is an apocalyptic number.

21202100121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21202100121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29534525669376).

21202100121020 is an abundant number, since it is smaller than the sum of its proper divisors (37866951217732).

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

21202100121020 is a wasteful number, since it uses less digits than its factorization.

21202100121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18221 (or 18219 counting only the distinct ones).

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

Adding to 21202100121020 its reverse (2012100120212), we get a palindrome (23214200241232).

The spelling of 21202100121020 in words is "twenty-one trillion, two hundred two billion, one hundred million, one hundred twenty-one thousand, twenty".