645107817 has 16 divisors (see below), whose sum is σ = 927501120. Its totient is φ = 397497600.

The previous prime is 645107791. The next prime is 645107821. The reversal of 645107817 is 718701546.

It is not a de Polignac number, because 645107817 - 2²⁴ = 628330601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645107317) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135684 + ... + 140357.

It is an arithmetic number, because the mean of its divisors is an integer number (57968820).

Almost surely, 2^645107817 is an apocalyptic number.

It is an amenable number.

645107817 is a deficient number, since it is larger than the sum of its proper divisors (282393303).

645107817 is a wasteful number, since it uses less digits than its factorization.

645107817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276104.

The product of its (nonzero) digits is 47040, while the sum is 39.

The square root of 645107817 is about 25398.9727548183. The cubic root of 645107817 is about 864.0603993163.

It can be divided in two parts, 64510 and 7817, that added together give a palindrome (72327).

The spelling of 645107817 in words is "six hundred forty-five million, one hundred seven thousand, eight hundred seventeen".