640129 has 8 divisors (see below), whose sum is σ = 770240. Its totient is φ = 519696.

The previous prime is 640127. The next prime is 640139. The reversal of 640129 is 921046.

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

It is a cyclic number.

It is not a de Polignac number, because 640129 - 2¹ = 640127 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640121) 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 7 ways as a sum of consecutive naturals, for example, 2274 + ... + 2539.

It is an arithmetic number, because the mean of its divisors is an integer number (96280).

2⁶⁴⁰¹²⁹ is an apocalyptic number.

It is an amenable number.

640129 is a deficient number, since it is larger than the sum of its proper divisors (130111).

640129 is a wasteful number, since it uses less digits than its factorization.

640129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4839.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 640129 is about 800.0806209377. The cubic root of 640129 is about 86.1831772555.

The spelling of 640129 in words is "six hundred forty thousand, one hundred twenty-nine".