521431680 has 256 divisors, whose sum is σ = 2072770560. Its totient is φ = 108318720.

The previous prime is 521431661. The next prime is 521431699. The reversal of 521431680 is 86134125.

It is an interprime number because it is at equal distance from previous prime (521431661) and next prime (521431699).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146077 + ... + 149603.

It is an arithmetic number, because the mean of its divisors is an integer number (8096760).

Almost surely, 2^521431680 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 521431680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1036385280).

521431680 is an abundant number, since it is smaller than the sum of its proper divisors (1551338880).

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

521431680 is a wasteful number, since it uses less digits than its factorization.

521431680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3567 (or 3555 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 521431680 is about 22834.8785851819. The cubic root of 521431680 is about 804.8824745162.

The spelling of 521431680 in words is "five hundred twenty-one million, four hundred thirty-one thousand, six hundred eighty".