645103331 has 2 divisors, whose sum is σ = 645103332. Its totient is φ = 645103330.

The previous prime is 645103313. The next prime is 645103351. The reversal of 645103331 is 133301546.

Together with previous prime (645103313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645103331 is a prime.

It is a super-2 number, since 2×645103331² = 832316615334591122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645103331.

It is not a weakly prime, because it can be changed into another prime (645103351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322551665 + 322551666.

It is an arithmetic number, because the mean of its divisors is an integer number (322551666).

Almost surely, 2^645103331 is an apocalyptic number.

645103331 is a deficient number, since it is larger than the sum of its proper divisors (1).

645103331 is an equidigital number, since it uses as much as digits as its factorization.

645103331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 645103331 is about 25398.8844440066. The cubic root of 645103331 is about 864.0583964552.

Adding to 645103331 its reverse (133301546), we get a palindrome (778404877).

The spelling of 645103331 in words is "six hundred forty-five million, one hundred three thousand, three hundred thirty-one".