521022421 has 4 divisors (see below), whose sum is σ = 521070732. Its totient is φ = 520974112.

The previous prime is 521022407. The next prime is 521022433. The reversal of 521022421 is 124220125.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 470456100 + 50566321 = 21690^2 + 7111^2 .

It is a cyclic number.

It is not a de Polignac number, because 521022421 - 2¹¹ = 521020373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521022521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225 + ... + 32281.

It is an arithmetic number, because the mean of its divisors is an integer number (130267683).

Almost surely, 2^521022421 is an apocalyptic number.

It is an amenable number.

521022421 is a deficient number, since it is larger than the sum of its proper divisors (48311).

521022421 is a wasteful number, since it uses less digits than its factorization.

521022421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48310.

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

The square root of 521022421 is about 22825.9155566650. The cubic root of 521022421 is about 804.6718418628.

Adding to 521022421 its reverse (124220125), we get a palindrome (645242546).

The spelling of 521022421 in words is "five hundred twenty-one million, twenty-two thousand, four hundred twenty-one".