645399265 has 8 divisors (see below), whose sum is σ = 885119040. Its totient is φ = 442559472.

The previous prime is 645399257. The next prime is 645399317. The reversal of 645399265 is 562993546.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 645399265 - 2³ = 645399257 is a prime.

It is a super-2 number, since 2×645399265² = 833080422525080450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9219955 + ... + 9220024.

It is an arithmetic number, because the mean of its divisors is an integer number (110639880).

Almost surely, 2^645399265 is an apocalyptic number.

It is an amenable number.

645399265 is a deficient number, since it is larger than the sum of its proper divisors (239719775).

645399265 is a wasteful number, since it uses less digits than its factorization.

645399265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18439991.

The product of its digits is 1749600, while the sum is 49.

The square root of 645399265 is about 25404.7095043419. The cubic root of 645399265 is about 864.1905019928.

The spelling of 645399265 in words is "six hundred forty-five million, three hundred ninety-nine thousand, two hundred sixty-five".