645449259 has 32 divisors (see below), whose sum is σ = 1095736320. Its totient is φ = 328712832.

The previous prime is 645449243. The next prime is 645449263. The reversal of 645449259 is 952944546.

645449259 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645449259 - 2⁴ = 645449243 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (645449239) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32847 + ... + 48680.

It is an arithmetic number, because the mean of its divisors is an integer number (34241760).

Almost surely, 2^645449259 is an apocalyptic number.

645449259 is a deficient number, since it is larger than the sum of its proper divisors (450287061).

645449259 is a wasteful number, since it uses less digits than its factorization.

645449259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81579.

The product of its digits is 1555200, while the sum is 48.

The square root of 645449259 is about 25405.6934367082. The cubic root of 645449259 is about 864.2128154282.

The spelling of 645449259 in words is "six hundred forty-five million, four hundred forty-nine thousand, two hundred fifty-nine".