645630 has 16 divisors (see below), whose sum is σ = 1549584. Its totient is φ = 172160.

The previous prime is 645629. The next prime is 645641. The reversal of 645630 is 36546.

It is a self number, because there is not a number n which added to its sum of digits gives 645630.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10731 + ... + 10790.

It is an arithmetic number, because the mean of its divisors is an integer number (96849).

2⁶⁴⁵⁶³⁰ is an apocalyptic number.

645630 is an abundant number, since it is smaller than the sum of its proper divisors (903954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645630 is a wasteful number, since it uses less digits than its factorization.

645630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21531.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 645630 is about 803.5110453503. The cubic root of 645630 is about 86.4293474550.

It can be divided in two parts, 645 and 630, that added together give a triangular number (1275 = T₅₀).

The spelling of 645630 in words is "six hundred forty-five thousand, six hundred thirty".