64651680 has 288 divisors, whose sum is σ = 247665600. Its totient is φ = 15261696.

The previous prime is 64651673. The next prime is 64651693. The reversal of 64651680 is 8615646.

64651680 is a `hidden beast` number, since 64 + 6 + 516 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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, 465051 + ... + 465189.

It is an arithmetic number, because the mean of its divisors is an integer number (859950).

Almost surely, 2^64651680 is an apocalyptic number.

64651680 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 64651680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123832800).

64651680 is an abundant number, since it is smaller than the sum of its proper divisors (183013920).

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

64651680 is a wasteful number, since it uses less digits than its factorization.

64651680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 64651680 is about 8040.6268412357. The cubic root of 64651680 is about 401.3530844121.

It can be divided in two parts, 646 and 51680, that added together give a triangular number (52326 = T₃₂₃).

The spelling of 64651680 in words is "sixty-four million, six hundred fifty-one thousand, six hundred eighty".