640018795 has 8 divisors (see below), whose sum is σ = 827101296. Its totient is φ = 472629216.

The previous prime is 640018793. The next prime is 640018801. The reversal of 640018795 is 597810046.

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 640018795 - 2¹ = 640018793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640018793) 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, 4923157 + ... + 4923286.

It is an arithmetic number, because the mean of its divisors is an integer number (103387662).

Almost surely, 2^640018795 is an apocalyptic number.

640018795 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

640018795 is a deficient number, since it is larger than the sum of its proper divisors (187082501).

640018795 is a wasteful number, since it uses less digits than its factorization.

640018795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9846461.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 640018795 is about 25298.5927474237. The cubic root of 640018795 is about 861.7823118885.

The spelling of 640018795 in words is "six hundred forty million, eighteen thousand, seven hundred ninety-five".