21001020001100 has 144 divisors (see below), whose sum is σ = 48177228460032. Its totient is φ = 7935564000000.

The previous prime is 21001020000923. The next prime is 21001020001139. The reversal of 21001020001100 is 110002010012.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21757745 + ... + 22702455.

It is an arithmetic number, because the mean of its divisors is an integer number (334564086528).

Almost surely, 2^{21001020001100} is an apocalyptic number.

21001020001100 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 21001020001100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24088614230016).

21001020001100 is an abundant number, since it is smaller than the sum of its proper divisors (27176208458932).

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

21001020001100 is a wasteful number, since it uses less digits than its factorization.

21001020001100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944928 (or 944921 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21001020001100 its reverse (110002010012), we get a palindrome (21111022011112).

The spelling of 21001020001100 in words is "twenty-one trillion, one billion, twenty million, one thousand, one hundred".