645378341 has 2 divisors, whose sum is σ = 645378342. Its totient is φ = 645378340.

The previous prime is 645378319. The next prime is 645378343. The reversal of 645378341 is 143873546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639837025 + 5541316 = 25295^2 + 2354^2 .

It is a cyclic number.

It is not a de Polignac number, because 645378341 - 2⁶ = 645378277 is a prime.

It is a Sophie Germain prime.

Together with 645378343, it forms a pair of twin primes.

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 (645378343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322689170 + 322689171.

It is an arithmetic number, because the mean of its divisors is an integer number (322689171).

Almost surely, 2^645378341 is an apocalyptic number.

It is an amenable number.

645378341 is a deficient number, since it is larger than the sum of its proper divisors (1).

645378341 is an equidigital number, since it uses as much as digits as its factorization.

645378341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 41.

The square root of 645378341 is about 25404.2976875961. The cubic root of 645378341 is about 864.1811628036.

The spelling of 645378341 in words is "six hundred forty-five million, three hundred seventy-eight thousand, three hundred forty-one".