6505712640 has 704 divisors, whose sum is σ = 27071493120. Its totient is φ = 1469104128.

The previous prime is 6505712639. The next prime is 6505712641. The reversal of 6505712640 is 462175056.

It is a happy number.

6505712640 is a `hidden beast` number, since 6 + 5 + 0 + 5 + 7 + 1 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (6505712639) and next prime (6505712641).

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

It is a junction number, because it is equal to n+sod(n) for n = 6505712595 and 6505712604.

It is not an unprimeable number, because it can be changed into a prime (6505712641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78382039 + ... + 78382121.

Almost surely, 2^6505712640 is an apocalyptic number.

6505712640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6505712640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13535746560).

6505712640 is an abundant number, since it is smaller than the sum of its proper divisors (20565780480).

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

6505712640 is an frugal number, since it uses more digits than its factorization.

6505712640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 6505712640 is about 80657.9979915197. The cubic root of 6505712640 is about 1866.8021488967.

Adding to 6505712640 its reverse (462175056), we get a palindrome (6967887696).

The spelling of 6505712640 in words is "six billion, five hundred five million, seven hundred twelve thousand, six hundred forty".