21001120120000 has 140 divisors (see below), whose sum is σ = 52226061841800. Its totient is φ = 8376233728000.

The previous prime is 21001120119979. The next prime is 21001120120009. The reversal of 21001120120000 is 2102110012.

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

It is not an unprimeable number, because it can be changed into a prime (21001120120009) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13123476 + ... + 14636524.

It is an arithmetic number, because the mean of its divisors is an integer number (373043298870).

Almost surely, 2^{21001120120000} is an apocalyptic number.

21001120120000 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 21001120120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26113030920900).

21001120120000 is an abundant number, since it is smaller than the sum of its proper divisors (31224941721800).

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

21001120120000 is an equidigital number, since it uses as much as digits as its factorization.

21001120120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1513428 (or 1513403 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21001120120000 its reverse (2102110012), we get a palindrome (21003222230012).

The spelling of 21001120120000 in words is "twenty-one trillion, one billion, one hundred twenty million, one hundred twenty thousand".