21345912200 has 36 divisors (see below), whose sum is σ = 49634050245. Its totient is φ = 8537538400.

The previous prime is 21345912199. The next prime is 21345912253. The reversal of 21345912200 is 221954312.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 20918993956 + 426918244 = 144634^2 + 20662^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103310.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2061035 + ... + 2071365.

Almost surely, 2^21345912200 is an apocalyptic number.

21345912200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21345912200 is an abundant number, since it is smaller than the sum of its proper divisors (28288138045).

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

21345912200 is an frugal number, since it uses more digits than its factorization.

21345912200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20678 (or 10338 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The spelling of 21345912200 in words is "twenty-one billion, three hundred forty-five million, nine hundred twelve thousand, two hundred".