645633044987 has 32 divisors (see below), whose sum is σ = 786066954624. Its totient is φ = 517651200000.

The previous prime is 645633044923. The next prime is 645633044993. The reversal of 645633044987 is 789440336546.

It is a cyclic number.

It is not a de Polignac number, because 645633044987 - 2⁶ = 645633044923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645633041987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113246237 + ... + 113251937.

It is an arithmetic number, because the mean of its divisors is an integer number (24564592332).

Almost surely, 2^645633044987 is an apocalyptic number.

645633044987 is a deficient number, since it is larger than the sum of its proper divisors (140433909637).

645633044987 is a wasteful number, since it uses less digits than its factorization.

645633044987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11399.

The product of its (nonzero) digits is 52254720, while the sum is 59.

The spelling of 645633044987 in words is "six hundred forty-five billion, six hundred thirty-three million, forty-four thousand, nine hundred eighty-seven".