521120421 has 12 divisors (see below), whose sum is σ = 755108172. Its totient is φ = 346315776.

The previous prime is 521120387. The next prime is 521120423. The reversal of 521120421 is 124021125.

521120421 is a `hidden beast` number, since 521 + 120 + 4 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 171243396 + 349877025 = 13086^2 + 18705^2 .

It is not a de Polignac number, because 521120421 - 2⁷ = 521120293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 521120394 and 521120403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521120423) 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 11 ways as a sum of consecutive naturals, for example, 88476 + ... + 94181.

It is an arithmetic number, because the mean of its divisors is an integer number (62925681).

Almost surely, 2^521120421 is an apocalyptic number.

It is an amenable number.

521120421 is a deficient number, since it is larger than the sum of its proper divisors (233987751).

521120421 is a wasteful number, since it uses less digits than its factorization.

521120421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182980 (or 182977 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 521120421 is about 22828.0621385171. The cubic root of 521120421 is about 804.7222894019.

Adding to 521120421 its reverse (124021125), we get a palindrome (645141546).

The spelling of 521120421 in words is "five hundred twenty-one million, one hundred twenty thousand, four hundred twenty-one".