645133 has 8 divisors (see below), whose sum is σ = 690552. Its totient is φ = 600576.

The previous prime is 645131. The next prime is 645137. The reversal of 645133 is 331546.

It can be written as a sum of positive squares in 4 ways, for example, as 100489 + 544644 = 317^2 + 738^2 .

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

It is not a de Polignac number, because 645133 - 2¹ = 645131 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 (645131) 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, 2191 + ... + 2467.

It is an arithmetic number, because the mean of its divisors is an integer number (86319).

2⁶⁴⁵¹³³ is an apocalyptic number.

It is an amenable number.

645133 is a deficient number, since it is larger than the sum of its proper divisors (45419).

645133 is a wasteful number, since it uses less digits than its factorization.

645133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431.

The product of its digits is 1080, while the sum is 22.

The square root of 645133 is about 803.2017181257. The cubic root of 645133 is about 86.4071642579.

Adding to 645133 its reverse (331546), we get a palindrome (976679).

It can be divided in two parts, 64513 and 3, that added together give a square (64516 = 254²).

The spelling of 645133 in words is "six hundred forty-five thousand, one hundred thirty-three".