645277 has 4 divisors (see below), whose sum is σ = 654976. Its totient is φ = 635580.

The previous prime is 645257. The next prime is 645313. The reversal of 645277 is 772546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645277 - 2⁷ = 645149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4749 + ... + 4882.

It is an arithmetic number, because the mean of its divisors is an integer number (163744).

2⁶⁴⁵²⁷⁷ is an apocalyptic number.

645277 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

645277 is a deficient number, since it is larger than the sum of its proper divisors (9699).

645277 is an equidigital number, since it uses as much as digits as its factorization.

645277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9698.

The product of its digits is 11760, while the sum is 31.

The square root of 645277 is about 803.2913543665. The cubic root of 645277 is about 86.4135927545.

The spelling of 645277 in words is "six hundred forty-five thousand, two hundred seventy-seven".