645626 has 12 divisors (see below), whose sum is σ = 1029678. Its totient is φ = 303552.

The previous prime is 645611. The next prime is 645629. The reversal of 645626 is 626546.

It can be written as a sum of positive squares in 3 ways, for example, as 555025 + 90601 = 745^2 + 301^2 .

It is not an unprimeable number, because it can be changed into a prime (645629) 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 5 ways as a sum of consecutive naturals, for example, 20 + ... + 1136.

2⁶⁴⁵⁶²⁶ is an apocalyptic number.

645626 is a deficient number, since it is larger than the sum of its proper divisors (384052).

645626 is a wasteful number, since it uses less digits than its factorization.

645626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153 (or 1136 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 645626 is about 803.5085562706. The cubic root of 645626 is about 86.4291689636.

The spelling of 645626 in words is "six hundred forty-five thousand, six hundred twenty-six".