645319 has 8 divisors (see below), whose sum is σ = 669600. Its totient is φ = 621600.

The previous prime is 645313. The next prime is 645329. The reversal of 645319 is 913546.

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 645319 - 2¹⁷ = 514247 is a prime.

It is a super-2 number, since 2×645319² = 832873223522, which contains 22 as substring.

It is a Duffinian number.

645319 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645313) 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, 4257 + ... + 4405.

It is an arithmetic number, because the mean of its divisors is an integer number (83700).

2⁶⁴⁵³¹⁹ is an apocalyptic number.

645319 is a deficient number, since it is larger than the sum of its proper divisors (24281).

645319 is a wasteful number, since it uses less digits than its factorization.

645319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281.

The product of its digits is 3240, while the sum is 28.

The square root of 645319 is about 803.3174963861. The cubic root of 645319 is about 86.4154675526.

The spelling of 645319 in words is "six hundred forty-five thousand, three hundred nineteen".