645943635 has 24 divisors (see below), whose sum is σ = 1145677104. Its totient is φ = 336490560.

The previous prime is 645943631. The next prime is 645943637. The reversal of 645943635 is 536349546.

645943635 is a `hidden beast` number, since 6 + 4 + 5 + 9 + 4 + 3 + 635 = 666.

It is not a de Polignac number, because 645943635 - 2² = 645943631 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (645943631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164976 + ... + 168845.

It is an arithmetic number, because the mean of its divisors is an integer number (47736546).

Almost surely, 2^645943635 is an apocalyptic number.

645943635 is a deficient number, since it is larger than the sum of its proper divisors (499733469).

645943635 is a wasteful number, since it uses less digits than its factorization.

645943635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333875 (or 333872 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 45.

The square root of 645943635 is about 25415.4212044577. The cubic root of 645943635 is about 864.4334044384.

The spelling of 645943635 in words is "six hundred forty-five million, nine hundred forty-three thousand, six hundred thirty-five".