645598 has 8 divisors (see below), whose sum is σ = 1001880. Its totient is φ = 311640.

The previous prime is 645583. The next prime is 645599. The reversal of 645598 is 895546.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5508 + ... + 5623.

It is an arithmetic number, because the mean of its divisors is an integer number (125235).

2⁶⁴⁵⁵⁹⁸ is an apocalyptic number.

645598 is a deficient number, since it is larger than the sum of its proper divisors (356282).

645598 is a wasteful number, since it uses less digits than its factorization.

645598 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11162.

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

The square root of 645598 is about 803.4911324962. The cubic root of 645598 is about 86.4279195036.

The spelling of 645598 in words is "six hundred forty-five thousand, five hundred ninety-eight".