11911645597 has 4 divisors (see below), whose sum is σ = 11911868380. Its totient is φ = 11911422816.

The previous prime is 11911645589. The next prime is 11911645607. The reversal of 11911645597 is 79554611911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79554611911 = 1867 ⋅42610933.

It can be written as a sum of positive squares in 2 ways, for example, as 1591930201 + 10319715396 = 39899^2 + 101586^2 .

It is a 3-Lehmer number, since φ(11911645597) divides (11911645597-1)³.

It is a cyclic number.

It is not a de Polignac number, because 11911645597 - 2³ = 11911645589 is a prime.

It is a super-3 number, since 3×11911645597³ (a number of 31 digits) contains 333 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 11911645597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11911645507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22279 + ... + 155947.

It is an arithmetic number, because the mean of its divisors is an integer number (2977967095).

It is a Poulet number, since it divides 2^11911645596-1.

Almost surely, 2^11911645597 is an apocalyptic number.

11911645597 is the 89113-rd pentagonal number.

It is an amenable number.

11911645597 is a deficient number, since it is larger than the sum of its proper divisors (222783).

11911645597 is an equidigital number, since it uses as much as digits as its factorization.

11911645597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222782.

The product of its digits is 340200, while the sum is 49.

The spelling of 11911645597 in words is "eleven billion, nine hundred eleven million, six hundred forty-five thousand, five hundred ninety-seven".