64165640 has 128 divisors (see below), whose sum is σ = 182891520. Its totient is φ = 19680000.

The previous prime is 64165639. The next prime is 64165643. The reversal of 64165640 is 4656146.

It is a junction number, because it is equal to n+sod(n) for n = 64165597 and 64165606.

It is not an unprimeable number, because it can be changed into a prime (64165643) 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, 255515 + ... + 255765.

It is an arithmetic number, because the mean of its divisors is an integer number (1428840).

Almost surely, 2^64165640 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 64165640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91445760).

64165640 is an abundant number, since it is smaller than the sum of its proper divisors (118725880).

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

64165640 is a wasteful number, since it uses less digits than its factorization.

64165640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 64165640 is about 8010.3458102631. The cubic root of 64165640 is about 400.3447860544.

The spelling of 64165640 in words is "sixty-four million, one hundred sixty-five thousand, six hundred forty".