21100111001020 has 24 divisors (see below), whose sum is σ = 46916717403024. Its totient is φ = 7943571200256.

The previous prime is 21100111000961. The next prime is 21100111001023. The reversal of 21100111001020 is 2010011100112.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21100111000988 and 21100111001006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100111001023) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 31029574662 + ... + 31029575341.

It is an arithmetic number, because the mean of its divisors is an integer number (1954863225126).

Almost surely, 2^{21100111001020} is an apocalyptic number.

21100111001020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100111001020 is an abundant number, since it is smaller than the sum of its proper divisors (25816606402004).

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

21100111001020 is a wasteful number, since it uses less digits than its factorization.

21100111001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62059150029 (or 62059150027 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21100111001020 its reverse (2010011100112), we get a palindrome (23110122101132).

The spelling of 21100111001020 in words is "twenty-one trillion, one hundred billion, one hundred eleven million, one thousand, twenty".