640029 has 8 divisors (see below), whose sum is σ = 919072. Its totient is φ = 393840.

The previous prime is 640027. The next prime is 640039. The reversal of 640029 is 920046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640029 - 2¹ = 640027 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639987 and 640014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640027) 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, 8167 + ... + 8244.

It is an arithmetic number, because the mean of its divisors is an integer number (114884).

2⁶⁴⁰⁰²⁹ is an apocalyptic number.

It is an amenable number.

640029 is a deficient number, since it is larger than the sum of its proper divisors (279043).

640029 is a wasteful number, since it uses less digits than its factorization.

640029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16427.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 640029 is about 800.0181247947. The cubic root of 640029 is about 86.1786892192.

The spelling of 640029 in words is "six hundred forty thousand, twenty-nine".