21011020000 has 120 divisors (see below), whose sum is σ = 51987889800. Its totient is φ = 8356032000.

The previous prime is 21011019973. The next prime is 21011020061. The reversal of 21011020000 is 2011012.

It is a super-2 number, since 2×21011020000² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3577066 + ... + 3582934.

It is an arithmetic number, because the mean of its divisors is an integer number (433232415).

Almost surely, 2^21011020000 is an apocalyptic number.

21011020000 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 21011020000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25993944900).

21011020000 is an abundant number, since it is smaller than the sum of its proper divisors (30976869800).

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

21011020000 is an equidigital number, since it uses as much as digits as its factorization.

21011020000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6078 (or 6055 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21011020000 its reverse (2011012), we get a palindrome (21013031012).

The spelling of 21011020000 in words is "twenty-one billion, eleven million, twenty thousand".