645004 has 12 divisors (see below), whose sum is σ = 1139544. Its totient is φ = 319424.

The previous prime is 644999. The next prime is 645011. The reversal of 645004 is 400546.

It is an Ulam number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 262 + ... + 1165.

It is an arithmetic number, because the mean of its divisors is an integer number (94962).

2⁶⁴⁵⁰⁰⁴ is an apocalyptic number.

It is an amenable number.

645004 is a deficient number, since it is larger than the sum of its proper divisors (494540).

645004 is a wasteful number, since it uses less digits than its factorization.

645004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544 (or 1542 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 645004 is about 803.1214104978. The cubic root of 645004 is about 86.4014045839.

The spelling of 645004 in words is "six hundred forty-five thousand, four".