6581645720 has 32 divisors (see below), whose sum is σ = 15947835120. Its totient is φ = 2430145920.

The previous prime is 6581645717. The next prime is 6581645723. The reversal of 6581645720 is 275461856.

It is an interprime number because it is at equal distance from previous prime (6581645717) and next prime (6581645723).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6581645723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6327986 + ... + 6329025.

Almost surely, 2^6581645720 is an apocalyptic number.

It is an amenable number.

6581645720 is an abundant number, since it is smaller than the sum of its proper divisors (9366189400).

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

6581645720 is a wasteful number, since it uses less digits than its factorization.

6581645720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12657035 (or 12657031 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 44.

The square root of 6581645720 is about 81127.3426164077. The cubic root of 6581645720 is about 1874.0370256327.

The spelling of 6581645720 in words is "six billion, five hundred eighty-one million, six hundred forty-five thousand, seven hundred twenty".