645543511 has 2 divisors, whose sum is σ = 645543512. Its totient is φ = 645543510.

The previous prime is 645543497. The next prime is 645543517. The reversal of 645543511 is 115345546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645543511 - 2⁹ = 645542999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645543517) 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, 322771755 + 322771756.

It is an arithmetic number, because the mean of its divisors is an integer number (322771756).

Almost surely, 2^645543511 is an apocalyptic number.

645543511 is a deficient number, since it is larger than the sum of its proper divisors (1).

645543511 is an equidigital number, since it uses as much as digits as its factorization.

645543511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 34.

The square root of 645543511 is about 25407.5483075404. The cubic root of 645543511 is about 864.2548790610.

The spelling of 645543511 in words is "six hundred forty-five million, five hundred forty-three thousand, five hundred eleven".