645895 has 8 divisors (see below), whose sum is σ = 783360. Its totient is φ = 511200.

The previous prime is 645893. The next prime is 645901. The reversal of 645895 is 598546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645895 - 2¹ = 645893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645893) 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 7 ways as a sum of consecutive naturals, for example, 135 + ... + 1144.

It is an arithmetic number, because the mean of its divisors is an integer number (97920).

2⁶⁴⁵⁸⁹⁵ is an apocalyptic number.

645895 is a deficient number, since it is larger than the sum of its proper divisors (137465).

645895 is a wasteful number, since it uses less digits than its factorization.

645895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385.

The product of its digits is 43200, while the sum is 37.

The square root of 645895 is about 803.6759297130. The cubic root of 645895 is about 86.4411708648.

It can be divided in two parts, 645 and 895, that multiplied together give a triangular number (577275 = T₁₀₇₄).

The spelling of 645895 in words is "six hundred forty-five thousand, eight hundred ninety-five".