521131320 has 160 divisors (see below), whose sum is σ = 1794759120. Its totient is φ = 135544320.

The previous prime is 521131291. The next prime is 521131339. The reversal of 521131320 is 23131125.

521131320 is a `hidden beast` number, since 521 + 13 + 132 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 521131293 and 521131302.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 130879 + ... + 134801.

Almost surely, 2^521131320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521131320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897379560).

521131320 is an abundant number, since it is smaller than the sum of its proper divisors (1273627800).

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

521131320 is a wasteful number, since it uses less digits than its factorization.

521131320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3987 (or 3974 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 521131320 is about 22828.3008566122. The cubic root of 521131320 is about 804.7278994981.

Adding to 521131320 its reverse (23131125), we get a palindrome (544262445).

It can be divided in two parts, 521 and 131320, that added together give a triangular number (131841 = T₅₁₃).

The spelling of 521131320 in words is "five hundred twenty-one million, one hundred thirty-one thousand, three hundred twenty".