645745968 has 60 divisors (see below), whose sum is σ = 2065365328. Its totient is φ = 184498560.

The previous prime is 645745957. The next prime is 645746009. The reversal of 645745968 is 869547546.

645745968 is a `hidden beast` number, since 6 + 4 + 574 + 5 + 9 + 68 = 666.

645745968 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 319303 + ... + 321318.

Almost surely, 2^645745968 is an apocalyptic number.

It is an amenable number.

645745968 is an abundant number, since it is smaller than the sum of its proper divisors (1419619360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645745968 is a wasteful number, since it uses less digits than its factorization.

645745968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640642 (or 640633 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 54.

The square root of 645745968 is about 25411.5321852107. The cubic root of 645745968 is about 864.3452195561.

It can be divided in two parts, 6457 and 45968, that added together give a palindrome (52425).

The spelling of 645745968 in words is "six hundred forty-five million, seven hundred forty-five thousand, nine hundred sixty-eight".