640792 has 16 divisors (see below), whose sum is σ = 1211040. Its totient is φ = 317856.

The previous prime is 640777. The next prime is 640793. The reversal of 640792 is 297046.

It is a super-3 number, since 3×640792³ = 789355243331019264, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an Ulam number.

640792 is a modest number, since divided by 792 gives 64 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 640792.

It is a congruent number.

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

640792 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1153 + ... + 1615.

It is an arithmetic number, because the mean of its divisors is an integer number (75690).

2⁶⁴⁰⁷⁹² is an apocalyptic number.

It is an amenable number.

640792 is a deficient number, since it is larger than the sum of its proper divisors (570248).

640792 is a wasteful number, since it uses less digits than its factorization.

640792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642 (or 638 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 640792 is about 800.4948469541. The cubic root of 640792 is about 86.2129211201.

The spelling of 640792 in words is "six hundred forty thousand, seven hundred ninety-two".