640057 has 8 divisors (see below), whose sum is σ = 721152. Its totient is φ = 562800.

The previous prime is 640049. The next prime is 640061. The reversal of 640057 is 750046.

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 640057 - 2³ = 640049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 598 + ... + 1279.

It is an arithmetic number, because the mean of its divisors is an integer number (90144).

2⁶⁴⁰⁰⁵⁷ is an apocalyptic number.

It is an amenable number.

640057 is a deficient number, since it is larger than the sum of its proper divisors (81095).

640057 is a wasteful number, since it uses less digits than its factorization.

640057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 640057 is about 800.0356242068. The cubic root of 640057 is about 86.1799459165.

The spelling of 640057 in words is "six hundred forty thousand, fifty-seven".