21200233609 has 3 divisors (see below), whose sum is σ = 21200379213. Its totient is φ = 21200088006.

The previous prime is 21200233597. The next prime is 21200233643. The reversal of 21200233609 is 90633200212.

The square root of 21200233609 is 145603.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 21200233609 - 2¹⁷ = 21200102537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21200233679) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 72802 + ... + 218404.

It is an arithmetic number, because the mean of its divisors is an integer number (7066793071).

Almost surely, 2^21200233609 is an apocalyptic number.

21200233609 is the 145603-rd square number.

21200233609 is the 72802-nd centered octagonal number.

It is an amenable number.

21200233609 is a deficient number, since it is larger than the sum of its proper divisors (145604).

21200233609 is an frugal number, since it uses more digits than its factorization.

21200233609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291206 (or 145603 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The spelling of 21200233609 in words is "twenty-one billion, two hundred million, two hundred thirty-three thousand, six hundred nine".