521671287 has 4 divisors (see below), whose sum is σ = 695561720. Its totient is φ = 347780856.

The previous prime is 521671237. The next prime is 521671291. The reversal of 521671287 is 782176125.

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

It is not a de Polignac number, because 521671287 - 2⁷ = 521671159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521671237) 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, 86945212 + ... + 86945217.

It is an arithmetic number, because the mean of its divisors is an integer number (173890430).

Almost surely, 2^521671287 is an apocalyptic number.

521671287 is a deficient number, since it is larger than the sum of its proper divisors (173890433).

521671287 is a wasteful number, since it uses less digits than its factorization.

521671287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173890432.

The product of its digits is 47040, while the sum is 39.

The square root of 521671287 is about 22840.1244961581. The cubic root of 521671287 is about 805.0057415071.

The spelling of 521671287 in words is "five hundred twenty-one million, six hundred seventy-one thousand, two hundred eighty-seven".