645927 has 4 divisors (see below), whose sum is σ = 861240. Its totient is φ = 430616.

The previous prime is 645907. The next prime is 645937. The reversal of 645927 is 729546.

645927 is nontrivially palindromic in base 15.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645927 - 2¹¹ = 643879 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107652 + ... + 107657.

It is an arithmetic number, because the mean of its divisors is an integer number (215310).

2⁶⁴⁵⁹²⁷ is an apocalyptic number.

645927 is a deficient number, since it is larger than the sum of its proper divisors (215313).

645927 is a wasteful number, since it uses less digits than its factorization.

645927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215312.

The product of its digits is 15120, while the sum is 33.

The square root of 645927 is about 803.6958379885. The cubic root of 645927 is about 86.4425983784.

The spelling of 645927 in words is "six hundred forty-five thousand, nine hundred twenty-seven".