640686046 has 96 divisors (see below), whose sum is σ = 1329914880. Its totient is φ = 225149760.

The previous prime is 640686041. The next prime is 640686077.

640686046 is nontrivially palindromic in base 10.

640686046 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 2×640686046² = 820957219078228232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640686041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1034725 + ... + 1035343.

It is an arithmetic number, because the mean of its divisors is an integer number (13853280).

Almost surely, 2^640686046 is an apocalyptic number.

640686046 is an abundant number, since it is smaller than the sum of its proper divisors (689228834).

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

640686046 is a wasteful number, since it uses less digits than its factorization.

640686046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 640686046 is about 25311.7768242374. The cubic root of 640686046 is about 862.0816913228.

It can be divided in two parts, 640 and 686046, that added together give a palindrome (686686).

The spelling of 640686046 in words is "six hundred forty million, six hundred eighty-six thousand, forty-six".