645738748 has 12 divisors (see below), whose sum is σ = 1130243632. Its totient is φ = 322812000.

The previous prime is 645738707. The next prime is 645738749. The reversal of 645738748 is 847837546.

It is a junction number, because it is equal to n+sod(n) for n = 645738695 and 645738704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645738749) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 20248 + ... + 41248.

Almost surely, 2^645738748 is an apocalyptic number.

It is an amenable number.

645738748 is a deficient number, since it is larger than the sum of its proper divisors (484504884).

645738748 is a wasteful number, since it uses less digits than its factorization.

645738748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28692 (or 28690 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 52.

The square root of 645738748 is about 25411.3901233286. The cubic root of 645738748 is about 864.3419981677.

The spelling of 645738748 in words is "six hundred forty-five million, seven hundred thirty-eight thousand, seven hundred forty-eight".