645610 has 32 divisors (see below), whose sum is σ = 1389312. Its totient is φ = 211200.

The previous prime is 645599. The next prime is 645611. The reversal of 645610 is 16546.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (645611) by changing a digit.

645610 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1410 + ... + 1810.

It is an arithmetic number, because the mean of its divisors is an integer number (43416).

2⁶⁴⁵⁶¹⁰ is an apocalyptic number.

645610 is an abundant number, since it is smaller than the sum of its proper divisors (743702).

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

645610 is a wasteful number, since it uses less digits than its factorization.

645610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 645610 is about 803.4985998743. The cubic root of 645610 is about 86.4284549909.

The spelling of 645610 in words is "six hundred forty-five thousand, six hundred ten".