645378343 has 2 divisors, whose sum is σ = 645378344. Its totient is φ = 645378342.

The previous prime is 645378341. The next prime is 645378359. The reversal of 645378343 is 343873546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645378343 - 2¹ = 645378341 is a prime.

It is a super-2 number, since 2×645378343² = 833026411226851298, which contains 22 as substring.

Together with 645378341, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 645378343.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645378341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322689171 + 322689172.

It is an arithmetic number, because the mean of its divisors is an integer number (322689172).

Almost surely, 2^645378343 is an apocalyptic number.

645378343 is a deficient number, since it is larger than the sum of its proper divisors (1).

645378343 is an equidigital number, since it uses as much as digits as its factorization.

645378343 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 43.

The square root of 645378343 is about 25404.2977269595. The cubic root of 645378343 is about 864.1811636963.

The spelling of 645378343 in words is "six hundred forty-five million, three hundred seventy-eight thousand, three hundred forty-three".