521379557 has 2 divisors, whose sum is σ = 521379558. Its totient is φ = 521379556.

The previous prime is 521379541. The next prime is 521379563. The reversal of 521379557 is 755973125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 498807556 + 22572001 = 22334^2 + 4751^2 .

It is a cyclic number.

It is not a de Polignac number, because 521379557 - 2⁴ = 521379541 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521879557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260689778 + 260689779.

It is an arithmetic number, because the mean of its divisors is an integer number (260689779).

Almost surely, 2^521379557 is an apocalyptic number.

It is an amenable number.

521379557 is a deficient number, since it is larger than the sum of its proper divisors (1).

521379557 is an equidigital number, since it uses as much as digits as its factorization.

521379557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 330750, while the sum is 44.

The square root of 521379557 is about 22833.7372543349. The cubic root of 521379557 is about 804.8556545838.

The spelling of 521379557 in words is "five hundred twenty-one million, three hundred seventy-nine thousand, five hundred fifty-seven".