521128469 has 2 divisors, whose sum is σ = 521128470. Its totient is φ = 521128468.

The previous prime is 521128381. The next prime is 521128483. The reversal of 521128469 is 964821125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 487835569 + 33292900 = 22087^2 + 5770^2 .

It is a cyclic number.

It is not a de Polignac number, because 521128469 - 2²⁰ = 520079893 is a prime.

It is a super-2 number, since 2×521128469² = 543149762404567922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521128169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260564234 + 260564235.

It is an arithmetic number, because the mean of its divisors is an integer number (260564235).

Almost surely, 2^521128469 is an apocalyptic number.

It is an amenable number.

521128469 is a deficient number, since it is larger than the sum of its proper divisors (1).

521128469 is an equidigital number, since it uses as much as digits as its factorization.

521128469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 38.

The square root of 521128469 is about 22828.2384121071. The cubic root of 521128469 is about 804.7264319963.

The spelling of 521128469 in words is "five hundred twenty-one million, one hundred twenty-eight thousand, four hundred sixty-nine".