645733057 has 2 divisors, whose sum is σ = 645733058. Its totient is φ = 645733056.

The previous prime is 645733043. The next prime is 645733087. The reversal of 645733057 is 750337546.

645733057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 555026481 + 90706576 = 23559^2 + 9524^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645733057 is a prime.

It is not a weakly prime, because it can be changed into another prime (645733037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322866528 + 322866529.

It is an arithmetic number, because the mean of its divisors is an integer number (322866529).

Almost surely, 2^645733057 is an apocalyptic number.

It is an amenable number.

645733057 is a deficient number, since it is larger than the sum of its proper divisors (1).

645733057 is an equidigital number, since it uses as much as digits as its factorization.

645733057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 264600, while the sum is 40.

The square root of 645733057 is about 25411.2781457368. The cubic root of 645733057 is about 864.3394589650.

The spelling of 645733057 in words is "six hundred forty-five million, seven hundred thirty-three thousand, fifty-seven".