645393 has 16 divisors (see below), whose sum is σ = 999296. Its totient is φ = 362880.

The previous prime is 645383. The next prime is 645397. The reversal of 645393 is 393546.

It is a happy number.

It is not a de Polignac number, because 645393 - 2⁶ = 645329 is a prime.

It is an Ulam number.

It is a Duffinian number.

645393 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 645393.

It is not an unprimeable number, because it can be changed into a prime (645397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1323 + ... + 1743.

It is an arithmetic number, because the mean of its divisors is an integer number (62456).

2⁶⁴⁵³⁹³ is an apocalyptic number.

It is an amenable number.

645393 is a deficient number, since it is larger than the sum of its proper divisors (353903).

645393 is a wasteful number, since it uses less digits than its factorization.

645393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504.

The product of its digits is 9720, while the sum is 30.

The square root of 645393 is about 803.3635540650. The cubic root of 645393 is about 86.4187705703.

The spelling of 645393 in words is "six hundred forty-five thousand, three hundred ninety-three".