640105026 has 32 divisors (see below), whose sum is σ = 1415734848. Its totient is φ = 191312640.

The previous prime is 640105013. The next prime is 640105033. The reversal of 640105026 is 620501046.

It is a junction number, because it is equal to n+sod(n) for n = 640104987 and 640105005.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61611 + ... + 71246.

It is an arithmetic number, because the mean of its divisors is an integer number (44241714).

Almost surely, 2^640105026 is an apocalyptic number.

640105026 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

640105026 is an abundant number, since it is smaller than the sum of its proper divisors (775629822).

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

640105026 is a wasteful number, since it uses less digits than its factorization.

640105026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132946.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 640105026 is about 25300.2969547790. The cubic root of 640105026 is about 861.8210133631.

The spelling of 640105026 in words is "six hundred forty million, one hundred five thousand, twenty-six".