645149 has 2 divisors, whose sum is σ = 645150. Its totient is φ = 645148.

The previous prime is 645137. The next prime is 645179. The reversal of 645149 is 941546.

645149 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 448900 + 196249 = 670^2 + 443^2 .

It is a cyclic number.

It is not a de Polignac number, because 645149 - 2¹⁶ = 579613 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322574 + 322575.

It is an arithmetic number, because the mean of its divisors is an integer number (322575).

2⁶⁴⁵¹⁴⁹ is an apocalyptic number.

It is an amenable number.

645149 is a deficient number, since it is larger than the sum of its proper divisors (1).

645149 is an equidigital number, since it uses as much as digits as its factorization.

645149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 645149 is about 803.2116782020. The cubic root of 645149 is about 86.4078785825.

The spelling of 645149 in words is "six hundred forty-five thousand, one hundred forty-nine".