11855997845 has 4 divisors (see below), whose sum is σ = 14227197420. Its totient is φ = 9484798272.

The previous prime is 11855997827. The next prime is 11855997871. The reversal of 11855997845 is 54879955811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54879955811 = 2441 ⋅22482571.

It can be written as a sum of positive squares in 2 ways, for example, as 9018731089 + 2837266756 = 94967^2 + 53266^2 .

It is a cyclic number.

It is not a de Polignac number, because 11855997845 - 2⁸ = 11855997589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1185599780 + ... + 1185599789.

It is an arithmetic number, because the mean of its divisors is an integer number (3556799355).

Almost surely, 2^11855997845 is an apocalyptic number.

It is an amenable number.

11855997845 is a deficient number, since it is larger than the sum of its proper divisors (2371199575).

11855997845 is an equidigital number, since it uses as much as digits as its factorization.

11855997845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371199574.

The product of its digits is 18144000, while the sum is 62.

The spelling of 11855997845 in words is "eleven billion, eight hundred fifty-five million, nine hundred ninety-seven thousand, eight hundred forty-five".