521405172 has 18 divisors (see below), whose sum is σ = 1317996498. Its totient is φ = 173801712.

The previous prime is 521405161. The next prime is 521405173. The reversal of 521405172 is 271504125.

521405172 is a `hidden beast` number, since 5 + 2 + 140 + 517 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 519566436 + 1838736 = 22794^2 + 1356^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521405173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7241703 + ... + 7241774.

Almost surely, 2^521405172 is an apocalyptic number.

It is an amenable number.

521405172 is an abundant number, since it is smaller than the sum of its proper divisors (796591326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521405172 is a wasteful number, since it uses less digits than its factorization.

521405172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14483487 (or 14483482 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 521405172 is about 22834.2981499323. The cubic root of 521405172 is about 804.8688350264.

Adding to 521405172 its reverse (271504125), we get a palindrome (792909297).

The spelling of 521405172 in words is "five hundred twenty-one million, four hundred five thousand, one hundred seventy-two".