11781717877 has 4 divisors (see below), whose sum is σ = 12055711360. Its totient is φ = 11507724396.

The previous prime is 11781717841. The next prime is 11781717953. The reversal of 11781717877 is 77871718711.

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, and also an emirpimes, since its reverse is a distinct semiprime: 77871718711 = 131899 ⋅590389.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11781717877 is a prime.

It is a super-2 number, since 2×11781717877² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11781717977) 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, 136996677 + ... + 136996762.

It is an arithmetic number, because the mean of its divisors is an integer number (3013927840).

Almost surely, 2^11781717877 is an apocalyptic number.

It is an amenable number.

11781717877 is a deficient number, since it is larger than the sum of its proper divisors (273993483).

11781717877 is an equidigital number, since it uses as much as digits as its factorization.

11781717877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273993482.

The product of its digits is 1075648, while the sum is 55.

The spelling of 11781717877 in words is "eleven billion, seven hundred eighty-one million, seven hundred seventeen thousand, eight hundred seventy-seven".