640558858 has 8 divisors (see below), whose sum is σ = 962505252. Its totient is φ = 319723776.

The previous prime is 640558829. The next prime is 640558903. The reversal of 640558858 is 858855046.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 556157889 + 84400969 = 23583^2 + 9187^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276385 + ... + 278692.

Almost surely, 2^640558858 is an apocalyptic number.

640558858 is a deficient number, since it is larger than the sum of its proper divisors (321946394).

640558858 is a wasteful number, since it uses less digits than its factorization.

640558858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555656.

The product of its (nonzero) digits is 1536000, while the sum is 49.

The square root of 640558858 is about 25309.2642721988. The cubic root of 640558858 is about 862.0246411741.

The spelling of 640558858 in words is "six hundred forty million, five hundred fifty-eight thousand, eight hundred fifty-eight".