21000000200000 has 84 divisors (see below), whose sum is σ = 52086510992124. Its totient is φ = 8400000000000.

The previous prime is 21000000199973. The next prime is 21000000200009. The reversal of 21000000200000 is 200000012.

It can be written as a sum of positive squares in 6 ways, for example, as 13869903989824 + 7130096210176 = 3724232^2 + 2670224^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000000200009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52300001 + ... + 52700000.

It is an arithmetic number, because the mean of its divisors is an integer number (620077511811).

Almost surely, 2^{21000000200000} is an apocalyptic number.

21000000200000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000000200000 is an abundant number, since it is smaller than the sum of its proper divisors (31086510792124).

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

21000000200000 is an frugal number, since it uses more digits than its factorization.

21000000200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105000038 (or 105000008 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

Adding to 21000000200000 its reverse (200000012), we get a palindrome (21000200200012).

The spelling of 21000000200000 in words is "twenty-one trillion, two hundred thousand".