645756794 has 8 divisors (see below), whose sum is σ = 971411700. Its totient is φ = 321952896.

The previous prime is 645756751. The next prime is 645756799. The reversal of 645756794 is 497657546.

It can be written as a sum of positive squares in 2 ways, for example, as 636906169 + 8850625 = 25237^2 + 2975^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (645756799) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 461879 + ... + 463274.

Almost surely, 2^645756794 is an apocalyptic number.

645756794 is a deficient number, since it is larger than the sum of its proper divisors (325654906).

645756794 is a wasteful number, since it uses less digits than its factorization.

645756794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925504.

The product of its digits is 6350400, while the sum is 53.

The square root of 645756794 is about 25411.7451978411. The cubic root of 645756794 is about 864.3500498090.

The spelling of 645756794 in words is "six hundred forty-five million, seven hundred fifty-six thousand, seven hundred ninety-four".