645015911 has 2 divisors, whose sum is σ = 645015912. Its totient is φ = 645015910.

The previous prime is 645015871. The next prime is 645015919. The reversal of 645015911 is 119510546.

645015911 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645015911 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p_33547532 and since 645015911 and 33547532 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645015919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322507955 + 322507956.

It is an arithmetic number, because the mean of its divisors is an integer number (322507956).

Almost surely, 2^645015911 is an apocalyptic number.

645015911 is a deficient number, since it is larger than the sum of its proper divisors (1).

645015911 is an equidigital number, since it uses as much as digits as its factorization.

645015911 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 645015911 is about 25397.1634439754. The cubic root of 645015911 is about 864.0193642601.

The spelling of 645015911 in words is "six hundred forty-five million, fifteen thousand, nine hundred eleven".