645111 has 8 divisors (see below), whose sum is σ = 955760. Its totient is φ = 430056.

The previous prime is 645097. The next prime is 645131. The reversal of 645111 is 111546.

It is not a de Polignac number, because 645111 - 2⁹ = 644599 is a prime.

It is a Duffinian number.

645111 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11920 + ... + 11973.

It is an arithmetic number, because the mean of its divisors is an integer number (119470).

2⁶⁴⁵¹¹¹ is an apocalyptic number.

645111 is a deficient number, since it is larger than the sum of its proper divisors (310649).

645111 is a wasteful number, since it uses less digits than its factorization.

645111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23902 (or 23896 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 645111 is about 803.1880228191. The cubic root of 645111 is about 86.4061820422.

Adding to 645111 its reverse (111546), we get a palindrome (756657).

The spelling of 645111 in words is "six hundred forty-five thousand, one hundred eleven".