21205320200 has 48 divisors (see below), whose sum is σ = 50110633860. Its totient is φ = 8343072000.

The previous prime is 21205320187. The next prime is 21205320211. The reversal of 21205320200 is 202350212.

It can be written as a sum of positive squares in 6 ways, for example, as 1510565956 + 19694754244 = 38866^2 + 140338^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 856871 + ... + 881270.

Almost surely, 2^21205320200 is an apocalyptic number.

21205320200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21205320200 is an abundant number, since it is smaller than the sum of its proper divisors (28905313660).

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

21205320200 is a wasteful number, since it uses less digits than its factorization.

21205320200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738218 (or 1738209 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

Adding to 21205320200 its reverse (202350212), we get a palindrome (21407670412).

The spelling of 21205320200 in words is "twenty-one billion, two hundred five million, three hundred twenty thousand, two hundred".