645922 has 8 divisors (see below), whose sum is σ = 976896. Its totient is φ = 320292.

The previous prime is 645907. The next prime is 645937. The reversal of 645922 is 229546.

645922 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645907) and next prime (645937).

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

It is an unprimeable number.

645922 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, 1018 + ... + 1525.

It is an arithmetic number, because the mean of its divisors is an integer number (122112).

2⁶⁴⁵⁹²² is an apocalyptic number.

645922 is a deficient number, since it is larger than the sum of its proper divisors (330974).

645922 is a wasteful number, since it uses less digits than its factorization.

645922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2672.

The product of its digits is 4320, while the sum is 28.

The square root of 645922 is about 803.6927273529. The cubic root of 645922 is about 86.4423753325.

The spelling of 645922 in words is "six hundred forty-five thousand, nine hundred twenty-two".