645385 has 8 divisors (see below), whose sum is σ = 834120. Its totient is φ = 476544.

The previous prime is 645383. The next prime is 645397. The reversal of 645385 is 583546.

It can be written as a sum of positive squares in 4 ways, for example, as 576 + 644809 = 24^2 + 803^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 645385 - 2¹ = 645383 is a prime.

645385 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (645383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4900 + ... + 5029.

It is an arithmetic number, because the mean of its divisors is an integer number (104265).

2⁶⁴⁵³⁸⁵ is an apocalyptic number.

645385 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

645385 is a deficient number, since it is larger than the sum of its proper divisors (188735).

645385 is a wasteful number, since it uses less digits than its factorization.

645385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9947.

The product of its digits is 14400, while the sum is 31.

The square root of 645385 is about 803.3585749838. The cubic root of 645385 is about 86.4184134994.

The spelling of 645385 in words is "six hundred forty-five thousand, three hundred eighty-five".