521555045145021 has 6 divisors (see below), whose sum is σ = 753357287431710. Its totient is φ = 347703363430008.

The previous prime is 521555045144971. The next prime is 521555045145023. The reversal of 521555045145021 is 120541540555125.

It is a happy number.

521555045145021 is a `hidden beast` number, since 5 + 2 + 1 + 5 + 550 + 4 + 51 + 45 + 0 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 320632499813796 + 200922545331225 = 17906214^2 + 14174715^2 .

It is not a de Polignac number, because 521555045145021 - 2²⁵ = 521555011590589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521555045145023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28975280285826 + ... + 28975280285843.

It is an arithmetic number, because the mean of its divisors is an integer number (125559547905285).

Almost surely, 2^{521555045145021} is an apocalyptic number.

It is an amenable number.

521555045145021 is a deficient number, since it is larger than the sum of its proper divisors (231802242286689).

521555045145021 is a wasteful number, since it uses less digits than its factorization.

521555045145021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57950560571675 (or 57950560571672 counting only the distinct ones).

The product of its (nonzero) digits is 1000000, while the sum is 45.

The spelling of 521555045145021 in words is "five hundred twenty-one trillion, five hundred fifty-five billion, forty-five million, one hundred forty-five thousand, twenty-one".