65640000 has 140 divisors (see below), whose sum is σ = 217417904. Its totient is φ = 17472000.

The previous prime is 65639993. The next prime is 65640019. The reversal of 65640000 is 4656.

It is a zygodrome in base 5.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 119727 + ... + 120273.

Almost surely, 2^65640000 is an apocalyptic number.

65640000 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 65640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108708952).

65640000 is an abundant number, since it is smaller than the sum of its proper divisors (151777904).

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

65640000 is an equidigital number, since it uses as much as digits as its factorization.

65640000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 65640000 is about 8101.8516402116. The cubic root of 65640000 is about 403.3878911392.

Adding to 65640000 its reverse (4656), we get a palindrome (65644656).

The spelling of 65640000 in words is "sixty-five million, six hundred forty thousand".