645965618 has 16 divisors (see below), whose sum is σ = 977262720. Its totient is φ = 320220000.

The previous prime is 645965611. The next prime is 645965623. The reversal of 645965618 is 816569546.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (645965611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179723 + ... + 183281.

It is an arithmetic number, because the mean of its divisors is an integer number (61078920).

Almost surely, 2^645965618 is an apocalyptic number.

645965618 is a deficient number, since it is larger than the sum of its proper divisors (331297102).

645965618 is a wasteful number, since it uses less digits than its factorization.

645965618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4313.

The product of its digits is 1555200, while the sum is 50.

The square root of 645965618 is about 25415.8536744293. The cubic root of 645965618 is about 864.4432105695.

The spelling of 645965618 in words is "six hundred forty-five million, nine hundred sixty-five thousand, six hundred eighteen".