11977557791 has 4 divisors (see below), whose sum is σ = 12682120032. Its totient is φ = 11272995552.

The previous prime is 11977557737. The next prime is 11977557797. The reversal of 11977557791 is 19775577911.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11977557791 - 2¹⁸ = 11977295647 is a prime.

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 11977557791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11977557797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352281095 + ... + 352281128.

It is an arithmetic number, because the mean of its divisors is an integer number (3170530008).

Almost surely, 2^11977557791 is an apocalyptic number.

11977557791 is a deficient number, since it is larger than the sum of its proper divisors (704562241).

11977557791 is an equidigital number, since it uses as much as digits as its factorization.

11977557791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704562240.

The product of its digits is 4862025, while the sum is 59.

It can be divided in two parts, 11 and 977557791, that multiplied together give a palindrome (10753135701).

The spelling of 11977557791 in words is "eleven billion, nine hundred seventy-seven million, five hundred fifty-seven thousand, seven hundred ninety-one".