645654 has 8 divisors (see below), whose sum is σ = 1291320. Its totient is φ = 215216.

The previous prime is 645649. The next prime is 645661. The reversal of 645654 is 456546.

645654 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

645654 is an admirable number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645654.

It is an unprimeable number.

645654 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 3 ways as a sum of consecutive naturals, for example, 53799 + ... + 53810.

It is an arithmetic number, because the mean of its divisors is an integer number (161415).

2⁶⁴⁵⁶⁵⁴ is an apocalyptic number.

645654 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

645654 is a wasteful number, since it uses less digits than its factorization.

645654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107614.

The product of its digits is 14400, while the sum is 30.

The square root of 645654 is about 803.5259796671. The cubic root of 645654 is about 86.4304183876.

The spelling of 645654 in words is "six hundred forty-five thousand, six hundred fifty-four".