640794 has 64 divisors (see below), whose sum is σ = 1704960. Its totient is φ = 155520.

The previous prime is 640793. The next prime is 640837. The reversal of 640794 is 497046.

640794 is nontrivially palindromic in base 8.

640794 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

640794 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (640793) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8742 + ... + 8814.

It is an arithmetic number, because the mean of its divisors is an integer number (26640).

2⁶⁴⁰⁷⁹⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640794, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (852480).

640794 is an abundant number, since it is smaller than the sum of its proper divisors (1064166).

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

640794 is a wasteful number, since it uses less digits than its factorization.

640794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 640794 is about 800.4960961804. The cubic root of 640794 is about 86.2130108141.

The spelling of 640794 in words is "six hundred forty thousand, seven hundred ninety-four".