30204821 has 4 divisors (see below), whose sum is σ = 30700044. Its totient is φ = 29709600.

The previous prime is 30204799. The next prime is 30204827. The reversal of 30204821 is 12840203.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10080625 + 20124196 = 3175^2 + 4486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30204821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 30204793 and 30204802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30204827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247520 + ... + 247641.

It is an arithmetic number, because the mean of its divisors is an integer number (7675011).

Almost surely, 2^30204821 is an apocalyptic number.

It is an amenable number.

30204821 is a deficient number, since it is larger than the sum of its proper divisors (495223).

30204821 is an equidigital number, since it uses as much as digits as its factorization.

30204821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495222.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 30204821 is about 5495.8912834953. The cubic root of 30204821 is about 311.4287878905.

The spelling of 30204821 in words is "thirty million, two hundred four thousand, eight hundred twenty-one".