40065664 has 32 divisors (see below), whose sum is σ = 80738100. Its totient is φ = 19802112.

The previous prime is 40065659. The next prime is 40065679. The reversal of 40065664 is 46656004.

It can be written as a sum of positive squares in 2 ways, for example, as 39438400 + 627264 = 6280^2 + 792^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9634 + ... + 13150.

Almost surely, 2^40065664 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 40065664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40369050).

40065664 is an abundant number, since it is smaller than the sum of its proper divisors (40672436).

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

40065664 is an equidigital number, since it uses as much as digits as its factorization.

40065664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3620 (or 3608 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 40065664 is about 6329.7443866242. The cubic root of 40065664 is about 342.1822267934.

The spelling of 40065664 in words is "forty million, sixty-five thousand, six hundred sixty-four".