30420521 has 2 divisors, whose sum is σ = 30420522. Its totient is φ = 30420520.

The previous prime is 30420491. The next prime is 30420529. The reversal of 30420521 is 12502403.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15713296 + 14707225 = 3964^2 + 3835^2 .

It is an emirp because it is prime and its reverse (12502403) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30420521 - 2⁶ = 30420457 is a prime.

It is a super-2 number, since 2×30420521² = 1850816195822882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 30420521.

It is not a weakly prime, because it can be changed into another prime (30420529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15210260 + 15210261.

It is an arithmetic number, because the mean of its divisors is an integer number (15210261).

Almost surely, 2^30420521 is an apocalyptic number.

It is an amenable number.

30420521 is a deficient number, since it is larger than the sum of its proper divisors (1).

30420521 is an equidigital number, since it uses as much as digits as its factorization.

30420521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 30420521 is about 5515.4801241596. The cubic root of 30420521 is about 312.1683598519.

Adding to 30420521 its reverse (12502403), we get a palindrome (42922924).

The spelling of 30420521 in words is "thirty million, four hundred twenty thousand, five hundred twenty-one".