645387999 has 8 divisors (see below), whose sum is σ = 860726832. Its totient is φ = 430153920.

The previous prime is 645387971. The next prime is 645388031. The reversal of 645387999 is 999783546.

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

It is not a de Polignac number, because 645387999 - 2⁷ = 645387871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645386999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10462 + ... + 37419.

It is an arithmetic number, because the mean of its divisors is an integer number (107590854).

Almost surely, 2^645387999 is an apocalyptic number.

645387999 is a deficient number, since it is larger than the sum of its proper divisors (215338833).

645387999 is a wasteful number, since it uses less digits than its factorization.

645387999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52377.

The product of its digits is 14696640, while the sum is 60.

The square root of 645387999 is about 25404.4877728326. The cubic root of 645387999 is about 864.1854735670.

The spelling of 645387999 in words is "six hundred forty-five million, three hundred eighty-seven thousand, nine hundred ninety-nine".