21001220110220 has 72 divisors (see below), whose sum is σ = 51484263851664. Its totient is φ = 7174975054464.

The previous prime is 21001220110201. The next prime is 21001220110231. The reversal of 21001220110220 is 2201102210012.

It is a super-2 number, since 2×21001220110220² (a number of 27 digits) contains 22 as substring.

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 = 21001220110195 and 21001220110204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37584527 + ... + 38139206.

It is an arithmetic number, because the mean of its divisors is an integer number (715059220162).

Almost surely, 2^{21001220110220} is an apocalyptic number.

21001220110220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001220110220 is an abundant number, since it is smaller than the sum of its proper divisors (30483043741444).

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

21001220110220 is a wasteful number, since it uses less digits than its factorization.

21001220110220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75724039 (or 75724030 counting only the distinct ones).

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

Adding to 21001220110220 its reverse (2201102210012), we get a palindrome (23202322320232).

The spelling of 21001220110220 in words is "twenty-one trillion, one billion, two hundred twenty million, one hundred ten thousand, two hundred twenty".