11721761055 has 48 divisors (see below), whose sum is σ = 21260828160. Its totient is φ = 5962951104.

The previous prime is 11721761039. The next prime is 11721761081. The reversal of 11721761055 is 55016712711.

It is a happy number.

11721761055 is a `hidden beast` number, since 1 + 17 + 21 + 7 + 610 + 5 + 5 = 666.

It is not a de Polignac number, because 11721761055 - 2⁴ = 11721761039 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 355792 + ... + 387338.

It is an arithmetic number, because the mean of its divisors is an integer number (442933920).

Almost surely, 2^11721761055 is an apocalyptic number.

11721761055 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

11721761055 is a deficient number, since it is larger than the sum of its proper divisors (9539067105).

11721761055 is a wasteful number, since it uses less digits than its factorization.

11721761055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31940 (or 31937 counting only the distinct ones).

The product of its (nonzero) digits is 14700, while the sum is 36.

The spelling of 11721761055 in words is "eleven billion, seven hundred twenty-one million, seven hundred sixty-one thousand, fifty-five".