2640545565517 has 2 divisors, whose sum is σ = 2640545565518. Its totient is φ = 2640545565516.

The previous prime is 2640545565509. The next prime is 2640545565571. The reversal of 2640545565517 is 7155655450462.

Together with next prime (2640545565571) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1713967982596 + 926577582921 = 1309186^2 + 962589^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640545565517 - 2³ = 2640545565509 is a prime.

It is a super-3 number, since 3×2640545565517³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2640545565017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1320272782758 + 1320272782759.

It is an arithmetic number, because the mean of its divisors is an integer number (1320272782759).

Almost surely, 2^{2640545565517} is an apocalyptic number.

It is an amenable number.

2640545565517 is a deficient number, since it is larger than the sum of its proper divisors (1).

2640545565517 is an equidigital number, since it uses as much as digits as its factorization.

2640545565517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25200000, while the sum is 55.

The spelling of 2640545565517 in words is "two trillion, six hundred forty billion, five hundred forty-five million, five hundred sixty-five thousand, five hundred seventeen".