11721177761 has 4 divisors (see below), whose sum is σ = 11734452912. Its totient is φ = 11707902612.

The previous prime is 11721177751. The next prime is 11721177869. The reversal of 11721177761 is 16777112711.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11721177761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11721177751) 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, 6636251 + ... + 6638016.

It is an arithmetic number, because the mean of its divisors is an integer number (2933613228).

Almost surely, 2^11721177761 is an apocalyptic number.

It is an amenable number.

11721177761 is a deficient number, since it is larger than the sum of its proper divisors (13275151).

11721177761 is an equidigital number, since it uses as much as digits as its factorization.

11721177761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13275150.

The product of its digits is 28812, while the sum is 41.

The spelling of 11721177761 in words is "eleven billion, seven hundred twenty-one million, one hundred seventy-seven thousand, seven hundred sixty-one".