997755760567 has 4 divisors (see below), whose sum is σ = 997758257760. Its totient is φ = 997753263376.

The previous prime is 997755760549. The next prime is 997755760571. The reversal of 997755760567 is 765067557799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 765067557799 = 96823 ⋅7901713.

It is a 4-Lehmer number, since φ(997755760567) divides (997755760567-1)⁴.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997755760567 is a prime.

It is a super-2 number, since 2×997755760567² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 997755760567.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997755760367) 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 in 3 ways as a sum of consecutive naturals, for example, 499438 + ... + 1498315.

It is an arithmetic number, because the mean of its divisors is an integer number (249439564440).

It is a Poulet number, since it divides 2^997755760566-1.

Almost surely, 2^997755760567 is an apocalyptic number.

997755760567 is the 499439-th decagonal number.

997755760567 is a deficient number, since it is larger than the sum of its proper divisors (2497193).

997755760567 is a wasteful number, since it uses less digits than its factorization.

997755760567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2497192.

The product of its (nonzero) digits is 875164500, while the sum is 73.

The spelling of 997755760567 in words is "nine hundred ninety-seven billion, seven hundred fifty-five million, seven hundred sixty thousand, five hundred sixty-seven".