645769744 has 15 divisors (see below), whose sum is σ = 1251375853. Its totient is φ = 322834048.

The previous prime is 645769723. The next prime is 645769757. The reversal of 645769744 is 447967546.

The square root of 645769744 is 25412.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 296528400 + 349241344 = 17220^2 + 18688^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645769691 and 645769700.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 98472 + ... + 104824.

Almost surely, 2^645769744 is an apocalyptic number.

645769744 is the 25412-nd square number.

It is an amenable number.

645769744 is a deficient number, since it is larger than the sum of its proper divisors (605606109).

645769744 is an frugal number, since it uses more digits than its factorization.

645769744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12714 (or 6355 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 52.

The cubic root of 645769744 is about 864.3558276594.

The spelling of 645769744 in words is "six hundred forty-five million, seven hundred sixty-nine thousand, seven hundred forty-four".