421202521 has 2 divisors, whose sum is σ = 421202522. Its totient is φ = 421202520.

The previous prime is 421202497. The next prime is 421202533. The reversal of 421202521 is 125202124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357777225 + 63425296 = 18915^2 + 7964^2 .

It is a cyclic number.

It is not a de Polignac number, because 421202521 - 2¹¹ = 421200473 is a prime.

It is not a weakly prime, because it can be changed into another prime (421202321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210601260 + 210601261.

It is an arithmetic number, because the mean of its divisors is an integer number (210601261).

Almost surely, 2^421202521 is an apocalyptic number.

It is an amenable number.

421202521 is a deficient number, since it is larger than the sum of its proper divisors (1).

421202521 is an equidigital number, since it uses as much as digits as its factorization.

421202521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 421202521 is about 20523.2190701167. The cubic root of 421202521 is about 749.6012819954.

Adding to 421202521 its reverse (125202124), we get a palindrome (546404645).

The spelling of 421202521 in words is "four hundred twenty-one million, two hundred two thousand, five hundred twenty-one".