10921718891 has 4 divisors (see below), whose sum is σ = 10937124000. Its totient is φ = 10906313784.

The previous prime is 10921718849. The next prime is 10921718897. The reversal of 10921718891 is 19881712901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19881712901 = 41039 ⋅484459.

It is a cyclic number.

It is not a de Polignac number, because 10921718891 - 2¹⁰ = 10921717867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10921718897) 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, 7701491 + ... + 7702908.

It is an arithmetic number, because the mean of its divisors is an integer number (2734281000).

Almost surely, 2^10921718891 is an apocalyptic number.

10921718891 is a deficient number, since it is larger than the sum of its proper divisors (15405109).

10921718891 is an equidigital number, since it uses as much as digits as its factorization.

10921718891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15405108.

The product of its (nonzero) digits is 72576, while the sum is 47.

The spelling of 10921718891 in words is "ten billion, nine hundred twenty-one million, seven hundred eighteen thousand, eight hundred ninety-one".