521404520993 has 2 divisors, whose sum is σ = 521404520994. Its totient is φ = 521404520992.

The previous prime is 521404520977. The next prime is 521404521031. The reversal of 521404520993 is 399025404125.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 346034533009 + 175369987984 = 588247^2 + 418772^2 .

It is a cyclic number.

It is not a de Polignac number, because 521404520993 - 2⁴ = 521404520977 is a prime.

It is not a weakly prime, because it can be changed into another prime (521404520953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260702260496 + 260702260497.

It is an arithmetic number, because the mean of its divisors is an integer number (260702260497).

Almost surely, 2^521404520993 is an apocalyptic number.

It is an amenable number.

521404520993 is a deficient number, since it is larger than the sum of its proper divisors (1).

521404520993 is an equidigital number, since it uses as much as digits as its factorization.

521404520993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 388800, while the sum is 44.

The spelling of 521404520993 in words is "five hundred twenty-one billion, four hundred four million, five hundred twenty thousand, nine hundred ninety-three".