5815664640 has 456 divisors, whose sum is σ = 22082968440. Its totient is φ = 1409286144.

The previous prime is 5815664629. The next prime is 5815664651. The reversal of 5815664640 is 464665185.

5815664640 is a `hidden beast` number, since 5 + 8 + 1 + 566 + 46 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (5815664629) and next prime (5815664651).

It can be written as a sum of positive squares in 4 ways, for example, as 1248067584 + 4567597056 = 35328^2 + 67584^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 200540146 + ... + 200540174.

Almost surely, 2^5815664640 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 5815664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11041484220).

5815664640 is an abundant number, since it is smaller than the sum of its proper divisors (16267303800).

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

5815664640 is an equidigital number, since it uses as much as digits as its factorization.

5815664640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 56 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The square root of 5815664640 is about 76260.5051124106. The cubic root of 5815664640 is about 1798.3178358548.

The spelling of 5815664640 in words is "five billion, eight hundred fifteen million, six hundred sixty-four thousand, six hundred forty".