522121021 has 4 divisors (see below), whose sum is σ = 530680444. Its totient is φ = 513561600.

The previous prime is 522120947. The next prime is 522121043. The reversal of 522121021 is 120121225.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 119115396 + 403005625 = 10914^2 + 20075^2 .

It is a cyclic number.

It is not a de Polignac number, because 522121021 - 2¹¹ = 522118973 is a prime.

It is a super-2 number, since 2×522121021² = 545220721140164882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 522120986 and 522121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (522121421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4279620 + ... + 4279741.

It is an arithmetic number, because the mean of its divisors is an integer number (132670111).

Almost surely, 2^522121021 is an apocalyptic number.

It is an amenable number.

522121021 is a deficient number, since it is larger than the sum of its proper divisors (8559423).

522121021 is an equidigital number, since it uses as much as digits as its factorization.

522121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8559422.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 522121021 is about 22849.9676367386. The cubic root of 522121021 is about 805.2370074868.

Adding to 522121021 its reverse (120121225), we get a palindrome (642242246).

The spelling of 522121021 in words is "five hundred twenty-two million, one hundred twenty-one thousand, twenty-one".