640106040 has 64 divisors (see below), whose sum is σ = 2194652160. Its totient is φ = 146309760.

The previous prime is 640106039. The next prime is 640106087. The reversal of 640106040 is 40601046.

640106040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 640105998 and 640106016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 380176 + ... + 381855.

It is an arithmetic number, because the mean of its divisors is an integer number (34291440).

Almost surely, 2^640106040 is an apocalyptic number.

640106040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640106040 is an abundant number, since it is smaller than the sum of its proper divisors (1554546120).

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

640106040 is a wasteful number, since it uses less digits than its factorization.

640106040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762052 (or 762048 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 640106040 is about 25300.3169940616. The cubic root of 640106040 is about 861.8214684374.

Adding to 640106040 its reverse (40601046), we get a palindrome (680707086).

The spelling of 640106040 in words is "six hundred forty million, one hundred six thousand, forty".