30320021 has 2 divisors, whose sum is σ = 30320022. Its totient is φ = 30320020.

The previous prime is 30320009. The next prime is 30320023. The reversal of 30320021 is 12002303.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29008996 + 1311025 = 5386^2 + 1145^2 .

It is a cyclic number.

It is not a de Polignac number, because 30320021 - 2²² = 26125717 is a prime.

Together with 30320023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 30319984 and 30320011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30320023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15160010 + 15160011.

It is an arithmetic number, because the mean of its divisors is an integer number (15160011).

Almost surely, 2^30320021 is an apocalyptic number.

It is an amenable number.

30320021 is a deficient number, since it is larger than the sum of its proper divisors (1).

30320021 is an equidigital number, since it uses as much as digits as its factorization.

30320021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 11.

The square root of 30320021 is about 5506.3618660600. The cubic root of 30320021 is about 311.8242113244.

Adding to 30320021 its reverse (12002303), we get a palindrome (42322324).

The spelling of 30320021 in words is "thirty million, three hundred twenty thousand, twenty-one".