11911810921 has 8 divisors (see below), whose sum is σ = 12037354560. Its totient is φ = 11786563152.

The previous prime is 11911810913. The next prime is 11911810927. The reversal of 11911810921 is 12901811911.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11911810921 - 2³ = 11911810913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11911810927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7446 + ... + 154528.

It is an arithmetic number, because the mean of its divisors is an integer number (1504669320).

Almost surely, 2^11911810921 is an apocalyptic number.

It is an amenable number.

11911810921 is a deficient number, since it is larger than the sum of its proper divisors (125543639).

11911810921 is a wasteful number, since it uses less digits than its factorization.

11911810921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147935.

The product of its (nonzero) digits is 1296, while the sum is 34.

The spelling of 11911810921 in words is "eleven billion, nine hundred eleven million, eight hundred ten thousand, nine hundred twenty-one".