111921521 has 2 divisors, whose sum is σ = 111921522. Its totient is φ = 111921520.

The previous prime is 111921503. The next prime is 111921569. The reversal of 111921521 is 125129111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111091600 + 829921 = 10540^2 + 911^2 .

It is a cyclic number.

It is not a de Polignac number, because 111921521 - 2¹⁴ = 111905137 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (111921581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55960760 + 55960761.

It is an arithmetic number, because the mean of its divisors is an integer number (55960761).

Almost surely, 2^111921521 is an apocalyptic number.

It is an amenable number.

111921521 is a deficient number, since it is larger than the sum of its proper divisors (1).

111921521 is an equidigital number, since it uses as much as digits as its factorization.

111921521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180, while the sum is 23.

The square root of 111921521 is about 10579.2968102800. The cubic root of 111921521 is about 481.9158398884.

The spelling of 111921521 in words is "one hundred eleven million, nine hundred twenty-one thousand, five hundred twenty-one".