64674640 has 80 divisors (see below), whose sum is σ = 158449680. Its totient is φ = 24514560.

The previous prime is 64674637. The next prime is 64674667. The reversal of 64674640 is 4647646.

It can be written as a sum of positive squares in 8 ways, for example, as 1567504 + 63107136 = 1252^2 + 7944^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 64674640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141292 + ... + 141748.

It is an arithmetic number, because the mean of its divisors is an integer number (1980621).

Almost surely, 2^64674640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64674640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79224840).

64674640 is an abundant number, since it is smaller than the sum of its proper divisors (93775040).

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

64674640 is a wasteful number, since it uses less digits than its factorization.

64674640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 554 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 37.

The square root of 64674640 is about 8042.0544638792. The cubic root of 64674640 is about 401.4005901442.

The spelling of 64674640 in words is "sixty-four million, six hundred seventy-four thousand, six hundred forty".