645055241 has 2 divisors, whose sum is σ = 645055242. Its totient is φ = 645055240.

The previous prime is 645055237. The next prime is 645055247. The reversal of 645055241 is 142550546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 536895241 + 108160000 = 23171^2 + 10400^2 .

It is a cyclic number.

It is not a de Polignac number, because 645055241 - 2² = 645055237 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 645055198 and 645055207.

It is not a weakly prime, because it can be changed into another prime (645055247) 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 as a sum of consecutive naturals, namely, 322527620 + 322527621.

It is an arithmetic number, because the mean of its divisors is an integer number (322527621).

Almost surely, 2^645055241 is an apocalyptic number.

It is an amenable number.

645055241 is a deficient number, since it is larger than the sum of its proper divisors (1).

645055241 is an equidigital number, since it uses as much as digits as its factorization.

645055241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24000, while the sum is 32.

The square root of 645055241 is about 25397.9377312411. The cubic root of 645055241 is about 864.0369251659.

The spelling of 645055241 in words is "six hundred forty-five million, fifty-five thousand, two hundred forty-one".