521025421245561 has 12 divisors (see below), whose sum is σ = 752598204526740. Its totient is φ = 347347544186880.

The previous prime is 521025421245551. The next prime is 521025421245569. The reversal of 521025421245561 is 165542124520125.

521025421245561 is a `hidden beast` number, since 5 + 2 + 1 + 0 + 2 + 5 + 42 + 1 + 2 + 45 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 262441944003600 + 258583477241961 = 16200060^2 + 16080531^2 .

It is not a de Polignac number, because 521025421245561 - 2¹¹ = 521025421243513 is a prime.

It is a super-2 number, since 2×521025421245561² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (521025421245569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 226847496 + ... + 229132793.

It is an arithmetic number, because the mean of its divisors is an integer number (62716517043895).

Almost surely, 2^{521025421245561} is an apocalyptic number.

It is an amenable number.

521025421245561 is a deficient number, since it is larger than the sum of its proper divisors (231572783281179).

521025421245561 is a wasteful number, since it uses less digits than its factorization.

521025421245561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456107256 (or 456107253 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 45.

Adding to 521025421245561 its reverse (165542124520125), we get a palindrome (686567545765686).

The spelling of 521025421245561 in words is "five hundred twenty-one trillion, twenty-five billion, four hundred twenty-one million, two hundred forty-five thousand, five hundred sixty-one".