521625557 has 4 divisors (see below), whose sum is σ = 521934636. Its totient is φ = 521316480.

The previous prime is 521625527. The next prime is 521625571. The reversal of 521625557 is 755526125.

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 269419396 + 252206161 = 16414^2 + 15881^2 .

It is a cyclic number.

It is not a de Polignac number, because 521625557 - 2¹⁰ = 521624533 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521625557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521625527) 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, 151994 + ... + 155387.

It is an arithmetic number, because the mean of its divisors is an integer number (130483659).

Almost surely, 2^521625557 is an apocalyptic number.

It is an amenable number.

521625557 is a deficient number, since it is larger than the sum of its proper divisors (309079).

521625557 is a wasteful number, since it uses less digits than its factorization.

521625557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309078.

The product of its digits is 105000, while the sum is 38.

The square root of 521625557 is about 22839.1233851039. The cubic root of 521625557 is about 804.9822184002.

The spelling of 521625557 in words is "five hundred twenty-one million, six hundred twenty-five thousand, five hundred fifty-seven".