65640960 has 480 divisors, whose sum is σ = 291088512. Its totient is φ = 13271040.

The previous prime is 65640889. The next prime is 65640979. The reversal of 65640960 is 6904656.

It is a happy number.

65640960 is a `hidden beast` number, since 6 + 5 + 640 + 9 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1774062 + ... + 1774098.

Almost surely, 2^65640960 is an apocalyptic number.

65640960 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 65640960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145544256).

65640960 is an abundant number, since it is smaller than the sum of its proper divisors (225447552).

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

65640960 is a wasteful number, since it uses less digits than its factorization.

65640960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 65640960 is about 8101.9108857109. The cubic root of 65640960 is about 403.3898576763.

It can be divided in two parts, 656 and 40960, that added together give a triangular number (41616 = T₂₈₈).

The spelling of 65640960 in words is "sixty-five million, six hundred forty thousand, nine hundred sixty".