581696640 has 480 divisors, whose sum is σ = 2427054300. Its totient is φ = 132378624.

The previous prime is 581696597. The next prime is 581696641. The reversal of 581696640 is 46696185.

581696640 is a `hidden beast` number, since 581 + 6 + 9 + 6 + 64 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 561121344 + 20575296 = 23688^2 + 4536^2 .

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (581696641) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2540046 + ... + 2540274.

Almost surely, 2^581696640 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 581696640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1213527150).

581696640 is an abundant number, since it is smaller than the sum of its proper divisors (1845357660).

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

581696640 is a wasteful number, since it uses less digits than its factorization.

581696640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 581696640 is about 24118.3880058349. The cubic root of 581696640 is about 834.7674732310.

The spelling of 581696640 in words is "five hundred eighty-one million, six hundred ninety-six thousand, six hundred forty".