640845023 has 8 divisors (see below), whose sum is σ = 788732448. Its totient is φ = 507042144.

The previous prime is 640845013. The next prime is 640845043. The reversal of 640845023 is 320548046.

640845023 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 640845023 - 2¹⁰ = 640843999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640845013) 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, 3521036 + ... + 3521217.

It is an arithmetic number, because the mean of its divisors is an integer number (98591556).

Almost surely, 2^640845023 is an apocalyptic number.

640845023 is a deficient number, since it is larger than the sum of its proper divisors (147887425).

640845023 is a wasteful number, since it uses less digits than its factorization.

640845023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7042273.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 640845023 is about 25314.9170055918. The cubic root of 640845023 is about 862.1529898045.

The spelling of 640845023 in words is "six hundred forty million, eight hundred forty-five thousand, twenty-three".