521294664 has 128 divisors (see below), whose sum is σ = 1542602880. Its totient is φ = 144998400.

The previous prime is 521294663. The next prime is 521294723. The reversal of 521294664 is 466492125.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (521294663) 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 31 ways as a sum of consecutive naturals, for example, 182592 + ... + 185424.

It is an arithmetic number, because the mean of its divisors is an integer number (12051585).

Almost surely, 2^521294664 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 521294664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771301440).

521294664 is an abundant number, since it is smaller than the sum of its proper divisors (1021308216).

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

521294664 is a wasteful number, since it uses less digits than its factorization.

521294664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2911 (or 2907 counting only the distinct ones).

The product of its digits is 103680, while the sum is 39.

The square root of 521294664 is about 22831.8782407405. The cubic root of 521294664 is about 804.8119689944.

The spelling of 521294664 in words is "five hundred twenty-one million, two hundred ninety-four thousand, six hundred sixty-four".