521432704 has 64 divisors (see below), whose sum is σ = 1184568840. Its totient is φ = 226492416.

The previous prime is 521432693. The next prime is 521432719. The reversal of 521432704 is 407234125.

It can be written as a sum of positive squares in 4 ways, for example, as 438986304 + 82446400 = 20952^2 + 9080^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 19072 + ... + 37504.

Almost surely, 2^521432704 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 521432704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (592284420).

521432704 is an abundant number, since it is smaller than the sum of its proper divisors (663136136).

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

521432704 is a wasteful number, since it uses less digits than its factorization.

521432704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18477 (or 18465 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 521432704 is about 22834.9010070112. The cubic root of 521432704 is about 804.8830013983.

Adding to 521432704 its reverse (407234125), we get a palindrome (928666829).

The spelling of 521432704 in words is "five hundred twenty-one million, four hundred thirty-two thousand, seven hundred four".