645747559 has 2 divisors, whose sum is σ = 645747560. Its totient is φ = 645747558.

The previous prime is 645747521. The next prime is 645747589. The reversal of 645747559 is 955747546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645747559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645747589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322873779 + 322873780.

It is an arithmetic number, because the mean of its divisors is an integer number (322873780).

Almost surely, 2^645747559 is an apocalyptic number.

645747559 is a deficient number, since it is larger than the sum of its proper divisors (1).

645747559 is an equidigital number, since it uses as much as digits as its factorization.

645747559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292000, while the sum is 52.

The square root of 645747559 is about 25411.5634898760. The cubic root of 645747559 is about 864.3459294184.

The spelling of 645747559 in words is "six hundred forty-five million, seven hundred forty-seven thousand, five hundred fifty-nine".