645264517663457 has 2 divisors, whose sum is σ = 645264517663458. Its totient is φ = 645264517663456.

The previous prime is 645264517663379. The next prime is 645264517663471. The reversal of 645264517663457 is 754366715462546.

It is a happy number.

645264517663457 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 can be written as a sum of positive squares in only one way, i.e., 385636747668496 + 259627769994961 = 19637636^2 + 16112969^2 .

It is a cyclic number.

It is not a de Polignac number, because 645264517663457 - 2¹⁰ = 645264517662433 is a prime.

It is not a weakly prime, because it can be changed into another prime (645264517663477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322632258831728 + 322632258831729.

It is an arithmetic number, because the mean of its divisors is an integer number (322632258831729).

Almost surely, 2^{645264517663457} is an apocalyptic number.

It is an amenable number.

645264517663457 is a deficient number, since it is larger than the sum of its proper divisors (1).

645264517663457 is an equidigital number, since it uses as much as digits as its factorization.

645264517663457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3048192000, while the sum is 71.

The spelling of 645264517663457 in words is "six hundred forty-five trillion, two hundred sixty-four billion, five hundred seventeen million, six hundred sixty-three thousand, four hundred fifty-seven".