640374 has 32 divisors (see below), whose sum is σ = 1489920. Its totient is φ = 179712.

The previous prime is 640369. The next prime is 640411. The reversal of 640374 is 473046.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640374.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3222 + ... + 3414.

It is an arithmetic number, because the mean of its divisors is an integer number (46560).

2⁶⁴⁰³⁷⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640374, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (744960).

640374 is an abundant number, since it is smaller than the sum of its proper divisors (849546).

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

640374 is a wasteful number, since it uses less digits than its factorization.

640374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284.

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 640374 is about 800.2337158606. The cubic root of 640374 is about 86.1941709694.

The spelling of 640374 in words is "six hundred forty thousand, three hundred seventy-four".