21020121020220 has 96 divisors (see below), whose sum is σ = 67267609360896. Its totient is φ = 4804368940800.

The previous prime is 21020121020191. The next prime is 21020121020231. The reversal of 21020121020220 is 2202012102012.

21020121020220 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

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 21020121020220.

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, 7657455 + ... + 10033785.

It is an arithmetic number, because the mean of its divisors is an integer number (700704264176).

Almost surely, 2^{21020121020220} is an apocalyptic number.

21020121020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020121020220 is an abundant number, since it is smaller than the sum of its proper divisors (46247488340676).

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

21020121020220 is a wasteful number, since it uses less digits than its factorization.

21020121020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397411 (or 2397409 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020121020220 its reverse (2202012102012), we get a palindrome (23222133122232).

The spelling of 21020121020220 in words is "twenty-one trillion, twenty billion, one hundred twenty-one million, twenty thousand, two hundred twenty".