30021521 has 2 divisors, whose sum is σ = 30021522. Its totient is φ = 30021520.

The previous prime is 30021517. The next prime is 30021529. The reversal of 30021521 is 12512003.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26635921 + 3385600 = 5161^2 + 1840^2 .

It is a cyclic number.

It is not a de Polignac number, because 30021521 - 2² = 30021517 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 30021496 and 30021505.

It is not a weakly prime, because it can be changed into another prime (30021529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15010760 + 15010761.

It is an arithmetic number, because the mean of its divisors is an integer number (15010761).

Almost surely, 2^30021521 is an apocalyptic number.

It is an amenable number.

30021521 is a deficient number, since it is larger than the sum of its proper divisors (1).

30021521 is an equidigital number, since it uses as much as digits as its factorization.

30021521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 30021521 is about 5479.1898123719. The cubic root of 30021521 is about 310.7975336697.

Adding to 30021521 its reverse (12512003), we get a palindrome (42533524).

The spelling of 30021521 in words is "thirty million, twenty-one thousand, five hundred twenty-one".