645718079 has 4 divisors (see below), whose sum is σ = 646653240. Its totient is φ = 644782920.

The previous prime is 645718067. The next prime is 645718081. The reversal of 645718079 is 970817546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645718079 - 2⁸ = 645717823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645718019) 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, 466544 + ... + 467925.

It is an arithmetic number, because the mean of its divisors is an integer number (161663310).

Almost surely, 2^645718079 is an apocalyptic number.

645718079 is a deficient number, since it is larger than the sum of its proper divisors (935161).

645718079 is an equidigital number, since it uses as much as digits as its factorization.

645718079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935160.

The product of its (nonzero) digits is 423360, while the sum is 47.

The square root of 645718079 is about 25410.9834323664. The cubic root of 645718079 is about 864.3327760298.

The spelling of 645718079 in words is "six hundred forty-five million, seven hundred eighteen thousand, seventy-nine".