645307 has 4 divisors (see below), whose sum is σ = 694960. Its totient is φ = 595656.

The previous prime is 645257. The next prime is 645313. The reversal of 645307 is 703546.

645307 is nontrivially palindromic in base 7.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 703546 = 2 ⋅351773.

It is a cyclic number.

It is not a de Polignac number, because 645307 - 2⁷ = 645179 is a prime.

It is a super-2 number, since 2×645307² = 832842248498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645347) 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, 24807 + ... + 24832.

It is an arithmetic number, because the mean of its divisors is an integer number (173740).

2⁶⁴⁵³⁰⁷ is an apocalyptic number.

645307 is a deficient number, since it is larger than the sum of its proper divisors (49653).

645307 is a wasteful number, since it uses less digits than its factorization.

645307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49652.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 645307 is about 803.3100273244. The cubic root of 645307 is about 86.4149319043.

The spelling of 645307 in words is "six hundred forty-five thousand, three hundred seven".