111421721 has 2 divisors, whose sum is σ = 111421722. Its totient is φ = 111421720.

The previous prime is 111421711. The next prime is 111421759. The reversal of 111421721 is 127124111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61011721 + 50410000 = 7811^2 + 7100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111421721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111421693 and 111421702.

It is not a weakly prime, because it can be changed into another prime (111421711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55710860 + 55710861.

It is an arithmetic number, because the mean of its divisors is an integer number (55710861).

Almost surely, 2^111421721 is an apocalyptic number.

It is an amenable number.

111421721 is a deficient number, since it is larger than the sum of its proper divisors (1).

111421721 is an equidigital number, since it uses as much as digits as its factorization.

111421721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 20.

The square root of 111421721 is about 10555.6487721030. The cubic root of 111421721 is about 481.1974169568.

Adding to 111421721 its reverse (127124111), we get a palindrome (238545832).

The spelling of 111421721 in words is "one hundred eleven million, four hundred twenty-one thousand, seven hundred twenty-one".