521306641 has 2 divisors, whose sum is σ = 521306642. Its totient is φ = 521306640.

The previous prime is 521306627. The next prime is 521306647. The reversal of 521306641 is 146603125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 514337041 + 6969600 = 22679^2 + 2640^2 .

It is a cyclic number.

It is not a de Polignac number, because 521306641 - 2¹¹ = 521304593 is a prime.

It is a super-2 number, since 2×521306641² = 543521227901405762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (521306647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260653320 + 260653321.

It is an arithmetic number, because the mean of its divisors is an integer number (260653321).

Almost surely, 2^521306641 is an apocalyptic number.

It is an amenable number.

521306641 is a deficient number, since it is larger than the sum of its proper divisors (1).

521306641 is an equidigital number, since it uses as much as digits as its factorization.

521306641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 521306641 is about 22832.1405260216. The cubic root of 521306641 is about 804.8181325968.

Adding to 521306641 its reverse (146603125), we get a palindrome (667909766).

The spelling of 521306641 in words is "five hundred twenty-one million, three hundred six thousand, six hundred forty-one".