645182 has 4 divisors (see below), whose sum is σ = 967776. Its totient is φ = 322590.

The previous prime is 645179. The next prime is 645187. The reversal of 645182 is 281546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 281546 = 2 ⋅140773.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645182.

It is not an unprimeable number, because it can be changed into a prime (645187) 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 as a sum of consecutive naturals, namely, 161294 + ... + 161297.

It is an arithmetic number, because the mean of its divisors is an integer number (241944).

2⁶⁴⁵¹⁸² is an apocalyptic number.

645182 is a deficient number, since it is larger than the sum of its proper divisors (322594).

645182 is a wasteful number, since it uses less digits than its factorization.

645182 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322593.

The product of its digits is 1920, while the sum is 26.

The square root of 645182 is about 803.2322204693. The cubic root of 645182 is about 86.4093518398.

The spelling of 645182 in words is "six hundred forty-five thousand, one hundred eighty-two".