645867 has 16 divisors (see below), whose sum is σ = 1008000. Its totient is φ = 407592.

The previous prime is 645857. The next prime is 645877. The reversal of 645867 is 768546.

It is a happy number.

645867 is a `hidden beast` number, since 645 + 8 + 6 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (645857) and next prime (645877).

It is not a de Polignac number, because 645867 - 2⁴ = 645851 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

645867 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645867.

It is not an unprimeable number, because it can be changed into a prime (645857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117 + ... + 1142.

It is an arithmetic number, because the mean of its divisors is an integer number (63000).

2⁶⁴⁵⁸⁶⁷ is an apocalyptic number.

645867 is a deficient number, since it is larger than the sum of its proper divisors (362133).

645867 is a wasteful number, since it uses less digits than its factorization.

645867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287 (or 1281 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 645867 is about 803.6585095673. The cubic root of 645867 is about 86.4399217516.

The spelling of 645867 in words is "six hundred forty-five thousand, eight hundred sixty-seven".