640165913 has 8 divisors (see below), whose sum is σ = 649902528. Its totient is φ = 630499024.

The previous prime is 640165901. The next prime is 640165927. The reversal of 640165913 is 319561046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640165913 - 2⁶ = 640165849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (640165963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1220 + ... + 35802.

It is an arithmetic number, because the mean of its divisors is an integer number (81237816).

Almost surely, 2^640165913 is an apocalyptic number.

It is an amenable number.

640165913 is a deficient number, since it is larger than the sum of its proper divisors (9736615).

640165913 is a wasteful number, since it uses less digits than its factorization.

640165913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34863.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 640165913 is about 25301.5002124380. The cubic root of 640165913 is about 861.8483380625.

The spelling of 640165913 in words is "six hundred forty million, one hundred sixty-five thousand, nine hundred thirteen".