521131968 has 168 divisors, whose sum is σ = 1770717312. Its totient is φ = 148863744.

The previous prime is 521131937. The next prime is 521131969. The reversal of 521131968 is 869131125.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521131969) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 106471 + ... + 111257.

It is an arithmetic number, because the mean of its divisors is an integer number (10539984).

Almost surely, 2^521131968 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 521131968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (885358656).

521131968 is an abundant number, since it is smaller than the sum of its proper divisors (1249585344).

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

521131968 is an equidigital number, since it uses as much as digits as its factorization.

521131968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4821 (or 4799 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 521131968 is about 22828.3150495169. The cubic root of 521131968 is about 804.7282330439.

The spelling of 521131968 in words is "five hundred twenty-one million, one hundred thirty-one thousand, nine hundred sixty-eight".