640579331 has 8 divisors (see below), whose sum is σ = 735561984. Its totient is φ = 546464520.

The previous prime is 640579327. The next prime is 640579333. The reversal of 640579331 is 133975046.

It is a happy number.

640579331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 640579331 - 2² = 640579327 is a prime.

It is a super-2 number, since 2×640579331² = 820683758608815122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640579333) 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, 215375 + ... + 218328.

It is an arithmetic number, because the mean of its divisors is an integer number (91945248).

Almost surely, 2^640579331 is an apocalyptic number.

640579331 is a deficient number, since it is larger than the sum of its proper divisors (94982653).

640579331 is a wasteful number, since it uses less digits than its factorization.

640579331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433921.

The product of its (nonzero) digits is 68040, while the sum is 38.

The square root of 640579331 is about 25309.6687256076. The cubic root of 640579331 is about 862.0338248436.

The spelling of 640579331 in words is "six hundred forty million, five hundred seventy-nine thousand, three hundred thirty-one".