111921913 has 12 divisors (see below), whose sum is σ = 118574820. Its totient is φ = 105626016.

The previous prime is 111921911. The next prime is 111921917. The reversal of 111921913 is 319129111.

It can be written as a sum of positive squares in 2 ways, for example, as 39790864 + 72131049 = 6308^2 + 8493^2 .

It is not a de Polignac number, because 111921913 - 2¹ = 111921911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (111921911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140031 + ... + 140827.

It is an arithmetic number, because the mean of its divisors is an integer number (9881235).

Almost surely, 2^111921913 is an apocalyptic number.

It is an amenable number.

111921913 is a deficient number, since it is larger than the sum of its proper divisors (6652907).

111921913 is an equidigital number, since it uses as much as digits as its factorization.

111921913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1224 (or 1205 counting only the distinct ones).

The product of its digits is 486, while the sum is 28.

The square root of 111921913 is about 10579.3153370150. The cubic root of 111921913 is about 481.9164025171.

It can be divided in two parts, 1119 and 21913, that added together give a palindrome (23032).

The spelling of 111921913 in words is "one hundred eleven million, nine hundred twenty-one thousand, nine hundred thirteen".