21020121202110 has 64 divisors (see below), whose sum is σ = 52476218383680. Its totient is φ = 5382176163840.

The previous prime is 21020121202049. The next prime is 21020121202123. The reversal of 21020121202110 is 1120212102012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21020121202110.

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, 66585787 + ... + 66900726.

It is an arithmetic number, because the mean of its divisors is an integer number (819940912245).

Almost surely, 2^{21020121202110} is an apocalyptic number.

21020121202110 is an abundant number, since it is smaller than the sum of its proper divisors (31456097181570).

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

21020121202110 is a wasteful number, since it uses less digits than its factorization.

21020121202110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133486733.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21020121202110 its reverse (1120212102012), we get a palindrome (22140333304122).

The spelling of 21020121202110 in words is "twenty-one trillion, twenty billion, one hundred twenty-one million, two hundred two thousand, one hundred ten".