522128921 has 2 divisors, whose sum is σ = 522128922. Its totient is φ = 522128920.

The previous prime is 522128851. The next prime is 522128947. The reversal of 522128921 is 129821225.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 518928400 + 3200521 = 22780^2 + 1789^2 .

It is a cyclic number.

It is not a de Polignac number, because 522128921 - 2¹⁰ = 522127897 is a prime.

It is a super-2 number, since 2×522128921² = 545237220289248482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (522128821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 261064460 + 261064461.

It is an arithmetic number, because the mean of its divisors is an integer number (261064461).

Almost surely, 2^522128921 is an apocalyptic number.

It is an amenable number.

522128921 is a deficient number, since it is larger than the sum of its proper divisors (1).

522128921 is an equidigital number, since it uses as much as digits as its factorization.

522128921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 32.

The square root of 522128921 is about 22850.1405028503. The cubic root of 522128921 is about 805.2410687038.

The spelling of 522128921 in words is "five hundred twenty-two million, one hundred twenty-eight thousand, nine hundred twenty-one".