645682507 has 4 divisors (see below), whose sum is σ = 650395656. Its totient is φ = 640969360.

The previous prime is 645682501. The next prime is 645682511. The reversal of 645682507 is 705286546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 705286546 = 2 ⋅352643273.

It is a cyclic number.

It is not a de Polignac number, because 645682507 - 2¹¹ = 645680459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645682501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2356369 + ... + 2356642.

It is an arithmetic number, because the mean of its divisors is an integer number (162598914).

Almost surely, 2^645682507 is an apocalyptic number.

645682507 is a deficient number, since it is larger than the sum of its proper divisors (4713149).

645682507 is a wasteful number, since it uses less digits than its factorization.

645682507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4713148.

The product of its (nonzero) digits is 403200, while the sum is 43.

The square root of 645682507 is about 25410.2834891703. The cubic root of 645682507 is about 864.3169039791.

The spelling of 645682507 in words is "six hundred forty-five million, six hundred eighty-two thousand, five hundred seven".