13961891121 has 32 divisors (see below), whose sum is σ = 20287987200. Its totient is φ = 8507566080.

The previous prime is 13961891113. The next prime is 13961891233. The reversal of 13961891121 is 12119816931.

It is a happy number.

It is not a de Polignac number, because 13961891121 - 2³ = 13961891113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13961895121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 217365 + ... + 274173.

It is an arithmetic number, because the mean of its divisors is an integer number (633999600).

Almost surely, 2^13961891121 is an apocalyptic number.

It is an amenable number.

13961891121 is a deficient number, since it is larger than the sum of its proper divisors (6326096079).

13961891121 is a wasteful number, since it uses less digits than its factorization.

13961891121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56969.

The product of its digits is 23328, while the sum is 42.

The spelling of 13961891121 in words is "thirteen billion, nine hundred sixty-one million, eight hundred ninety-one thousand, one hundred twenty-one".