65815680 has 256 divisors, whose sum is σ = 246758400. Its totient is φ = 14610432.

The previous prime is 65815669. The next prime is 65815681. The reversal of 65815680 is 8651856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65815681) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 792919 + ... + 793001.

It is an arithmetic number, because the mean of its divisors is an integer number (963900).

Almost surely, 2^65815680 is an apocalyptic number.

65815680 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 65815680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123379200).

65815680 is an abundant number, since it is smaller than the sum of its proper divisors (180942720).

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

65815680 is a wasteful number, since it uses less digits than its factorization.

65815680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 39.

The square root of 65815680 is about 8112.6863614958. The cubic root of 65815680 is about 403.7474486000.

The spelling of 65815680 in words is "sixty-five million, eight hundred fifteen thousand, six hundred eighty".