645601886 has 16 divisors (see below), whose sum is σ = 1005974640. Its totient is φ = 310369920.

The previous prime is 645601861. The next prime is 645601897. The reversal of 645601886 is 688106546.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9116 + ... + 37071.

It is an arithmetic number, because the mean of its divisors is an integer number (62873415).

Almost surely, 2^645601886 is an apocalyptic number.

645601886 is a deficient number, since it is larger than the sum of its proper divisors (360372754).

645601886 is a wasteful number, since it uses less digits than its factorization.

645601886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46459.

The product of its (nonzero) digits is 276480, while the sum is 44.

The square root of 645601886 is about 25408.6970543552. The cubic root of 645601886 is about 864.2809291294.

The spelling of 645601886 in words is "six hundred forty-five million, six hundred one thousand, eight hundred eighty-six".