640154 has 8 divisors (see below), whose sum is σ = 964128. Its totient is φ = 318780.

The previous prime is 640153. The next prime is 640163. The reversal of 640154 is 451046.

It is a happy number.

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

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640154.

It is not an unprimeable number, because it can be changed into a prime (640151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179 + ... + 1145.

It is an arithmetic number, because the mean of its divisors is an integer number (120516).

2⁶⁴⁰¹⁵⁴ is an apocalyptic number.

640154 is a deficient number, since it is larger than the sum of its proper divisors (323974).

640154 is a wasteful number, since it uses less digits than its factorization.

640154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 640154 is about 800.0962442107. The cubic root of 640154 is about 86.1842991916.

The spelling of 640154 in words is "six hundred forty thousand, one hundred fifty-four".