11920911921 has 24 divisors (see below), whose sum is σ = 18244721664. Its totient is φ = 7474561920.

The previous prime is 11920911917. The next prime is 11920911929. The reversal of 11920911921 is 12911902911.

It is not a de Polignac number, because 11920911921 - 2² = 11920911917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11920911929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198580 + ... + 251546.

It is an arithmetic number, because the mean of its divisors is an integer number (760196736).

Almost surely, 2^11920911921 is an apocalyptic number.

It is an amenable number.

11920911921 is a deficient number, since it is larger than the sum of its proper divisors (6323809743).

11920911921 is a wasteful number, since it uses less digits than its factorization.

11920911921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54461 (or 54458 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 36.

The spelling of 11920911921 in words is "eleven billion, nine hundred twenty million, nine hundred eleven thousand, nine hundred twenty-one".