520125132505721 has 4 divisors (see below), whose sum is σ = 538060481902500. Its totient is φ = 502189783108944.

The previous prime is 520125132505717. The next prime is 520125132505787. The reversal of 520125132505721 is 127505231521025.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 437704517689321 + 82420614816400 = 20921389^2 + 9078580^2 .

It is a cyclic number.

It is not a de Polignac number, because 520125132505721 - 2² = 520125132505717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (520125132525721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8967674698346 + ... + 8967674698403.

It is an arithmetic number, because the mean of its divisors is an integer number (134515120475625).

Almost surely, 2^{520125132505721} is an apocalyptic number.

It is an amenable number.

520125132505721 is a deficient number, since it is larger than the sum of its proper divisors (17935349396779).

520125132505721 is a wasteful number, since it uses less digits than its factorization.

520125132505721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17935349396778.

The product of its (nonzero) digits is 210000, while the sum is 41.

The spelling of 520125132505721 in words is "five hundred twenty trillion, one hundred twenty-five billion, one hundred thirty-two million, five hundred five thousand, seven hundred twenty-one".