11771609921 has 4 divisors (see below), whose sum is σ = 12283419072. Its totient is φ = 11259800772.

The previous prime is 11771609911. The next prime is 11771609929. The reversal of 11771609921 is 12990617711.

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-11771609921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11771609929) 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, 255904541 + ... + 255904586.

It is an arithmetic number, because the mean of its divisors is an integer number (3070854768).

Almost surely, 2^11771609921 is an apocalyptic number.

It is an amenable number.

11771609921 is a deficient number, since it is larger than the sum of its proper divisors (511809151).

11771609921 is an equidigital number, since it uses as much as digits as its factorization.

11771609921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511809150.

The product of its (nonzero) digits is 47628, while the sum is 44.

The spelling of 11771609921 in words is "eleven billion, seven hundred seventy-one million, six hundred nine thousand, nine hundred twenty-one".