640017818 has 16 divisors (see below), whose sum is σ = 1047691584. Its totient is φ = 290808960.

The previous prime is 640017811. The next prime is 640017821. The reversal of 640017818 is 818710046.

640017818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×640017818² = 819245614714962248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640017811) 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, 106346 + ... + 112202.

It is an arithmetic number, because the mean of its divisors is an integer number (65480724).

Almost surely, 2^640017818 is an apocalyptic number.

640017818 is a deficient number, since it is larger than the sum of its proper divisors (407673766).

640017818 is a wasteful number, since it uses less digits than its factorization.

640017818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10837.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 640017818 is about 25298.5734380419. The cubic root of 640017818 is about 861.7818733796.

The spelling of 640017818 in words is "six hundred forty million, seventeen thousand, eight hundred eighteen".