645696 has 84 divisors (see below), whose sum is σ = 1981200. Its totient is φ = 200448.

The previous prime is 645691. The next prime is 645703. The reversal of 645696 is 696546.

It is a happy number.

645696 is a `hidden beast` number, since 645 + 6 + 9 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (38880) is a multiple of the sum of its prime factors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 645696.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645696.

It is not an unprimeable number, because it can be changed into a prime (645691) by changing a digit.

645696 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 11 ways as a sum of consecutive naturals, for example, 10915 + ... + 10973.

2⁶⁴⁵⁶⁹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (990600).

645696 is an abundant number, since it is smaller than the sum of its proper divisors (1335504).

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

645696 is a wasteful number, since it uses less digits than its factorization.

645696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 83 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 645696 is about 803.5521140536. The cubic root of 645696 is about 86.4322924558.

The spelling of 645696 in words is "six hundred forty-five thousand, six hundred ninety-six".