645883858 has 8 divisors (see below), whose sum is σ = 979711740. Its totient is φ = 319313280.

The previous prime is 645883831. The next prime is 645883879. The reversal of 645883858 is 858388546.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 586947529 + 58936329 = 24227^2 + 7677^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 645883799 and 645883808.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1814103 + ... + 1814458.

Almost surely, 2^645883858 is an apocalyptic number.

645883858 is a deficient number, since it is larger than the sum of its proper divisors (333827882).

645883858 is a wasteful number, since it uses less digits than its factorization.

645883858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3628652.

The product of its digits is 7372800, while the sum is 55.

The square root of 645883858 is about 25414.2451786395. The cubic root of 645883858 is about 864.4067381129.

The spelling of 645883858 in words is "six hundred forty-five million, eight hundred eighty-three thousand, eight hundred fifty-eight".