21011200000 has 432 divisors, whose sum is σ = 61996891320. Its totient is φ = 7096320000.

The previous prime is 21011199991. The next prime is 21011200043. The reversal of 21011200000 is 211012.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 313599967 + ... + 313600033.

Almost surely, 2^21011200000 is an apocalyptic number.

21011200000 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 21011200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30998445660).

21011200000 is an abundant number, since it is smaller than the sum of its proper divisors (40985691320).

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

21011200000 is an frugal number, since it uses more digits than its factorization.

21011200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 81 counting only the distinct ones).

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

Adding to 21011200000 its reverse (211012), we get a palindrome (21011411012).

The spelling of 21011200000 in words is "twenty-one billion, eleven million, two hundred thousand".