305200021 has 16 divisors (see below), whose sum is σ = 370739200. Its totient is φ = 245414448.

The previous prime is 305199967. The next prime is 305200039. The reversal of 305200021 is 120002503.

It is a cyclic number.

It is not a de Polignac number, because 305200021 - 2¹⁵ = 305167253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 305199974 and 305200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (303200021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2560 + ... + 24838.

It is an arithmetic number, because the mean of its divisors is an integer number (23171200).

Almost surely, 2^305200021 is an apocalyptic number.

It is an amenable number.

305200021 is a deficient number, since it is larger than the sum of its proper divisors (65539179).

305200021 is a wasteful number, since it uses less digits than its factorization.

305200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22408.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 305200021 is about 17469.9748425692. The cubic root of 305200021 is about 673.2786655995.

Adding to 305200021 its reverse (120002503), we get a palindrome (425202524).

The spelling of 305200021 in words is "three hundred five million, two hundred thousand, twenty-one".