521521321345 has 8 divisors (see below), whose sum is σ = 662638855464. Its totient is φ = 392674877184.

The previous prime is 521521321313. The next prime is 521521321393. The reversal of 521521321345 is 543123125125.

It can be written as a sum of positive squares in 4 ways, for example, as 13175137089 + 508346184256 = 114783^2 + 712984^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 521521321345 - 2⁵ = 521521321313 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 521521321345.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3067772394 + ... + 3067772563.

It is an arithmetic number, because the mean of its divisors is an integer number (82829856933).

Almost surely, 2^521521321345 is an apocalyptic number.

It is an amenable number.

521521321345 is a deficient number, since it is larger than the sum of its proper divisors (141117534119).

521521321345 is a wasteful number, since it uses less digits than its factorization.

521521321345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6135544979.

The product of its digits is 36000, while the sum is 34.

The spelling of 521521321345 in words is "five hundred twenty-one billion, five hundred twenty-one million, three hundred twenty-one thousand, three hundred forty-five".