521681076 has 72 divisors (see below), whose sum is σ = 1510052544. Its totient is φ = 148757760.

The previous prime is 521681053. The next prime is 521681077. The reversal of 521681076 is 670186125.

521681076 is a `hidden beast` number, since 521 + 68 + 1 + 0 + 76 = 666.

It is a super-2 number, since 2×521681076² = 544302290113035552, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 521681076.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521681077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 147691 + ... + 151181.

It is an arithmetic number, because the mean of its divisors is an integer number (20972952).

Almost surely, 2^521681076 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 521681076, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (755026272).

521681076 is an abundant number, since it is smaller than the sum of its proper divisors (988371468).

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

521681076 is a wasteful number, since it uses less digits than its factorization.

521681076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4101 (or 4096 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 521681076 is about 22840.3387890810. The cubic root of 521681076 is about 805.0107767033.

The spelling of 521681076 in words is "five hundred twenty-one million, six hundred eighty-one thousand, seventy-six".