640845592558 has 4 divisors (see below), whose sum is σ = 961268388840. Its totient is φ = 320422796278.

The previous prime is 640845592547. The next prime is 640845592579. The reversal of 640845592558 is 855295548046.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 640845592496 and 640845592505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160211398138 + ... + 160211398141.

It is an arithmetic number, because the mean of its divisors is an integer number (240317097210).

Almost surely, 2^640845592558 is an apocalyptic number.

640845592558 is a deficient number, since it is larger than the sum of its proper divisors (320422796282).

640845592558 is a wasteful number, since it uses less digits than its factorization.

640845592558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320422796281.

The product of its (nonzero) digits is 69120000, while the sum is 61.

The spelling of 640845592558 in words is "six hundred forty billion, eight hundred forty-five million, five hundred ninety-two thousand, five hundred fifty-eight".