640012 has 18 divisors (see below), whose sum is σ = 1165164. Its totient is φ = 307440.

The previous prime is 640009. The next prime is 640019. The reversal of 640012 is 210046.

It is an Ulam number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 639974 and 640001.

It is not an unprimeable number, because it can be changed into a prime (640019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10462 + ... + 10522.

2⁶⁴⁰⁰¹² is an apocalyptic number.

It is an amenable number.

640012 is a deficient number, since it is larger than the sum of its proper divisors (525152).

640012 is a wasteful number, since it uses less digits than its factorization.

640012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 640012 is about 800.0074999648. The cubic root of 640012 is about 86.1779262066.

Adding to 640012 its reverse (210046), we get a palindrome (850058).

The spelling of 640012 in words is "six hundred forty thousand, twelve".