6565940640 has 576 divisors, whose sum is σ = 27051687936. Its totient is φ = 1417844736.

The previous prime is 6565940621. The next prime is 6565940657. The reversal of 6565940640 is 460495656.

6565940640 is a `hidden beast` number, since 6 + 56 + 594 + 0 + 6 + 4 + 0 = 666.

It is a super-2 number, since 2×6565940640² = 86223152976007219200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 29443569 + ... + 29443791.

It is an arithmetic number, because the mean of its divisors is an integer number (46964736).

Almost surely, 2^6565940640 is an apocalyptic number.

6565940640 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 6565940640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13525843968).

6565940640 is an abundant number, since it is smaller than the sum of its proper divisors (20485747296).

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

6565940640 is a wasteful number, since it uses less digits than its factorization.

6565940640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 45.

The square root of 6565940640 is about 81030.4920384913. The cubic root of 6565940640 is about 1872.5452334672.

The spelling of 6565940640 in words is "six billion, five hundred sixty-five million, nine hundred forty thousand, six hundred forty".