111001220021 has 2 divisors, whose sum is σ = 111001220022. Its totient is φ = 111001220020.

The previous prime is 111001219997. The next prime is 111001220047. The reversal of 111001220021 is 120022100111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108893400100 + 2107819921 = 329990^2 + 45911^2 .

It is a cyclic number.

It is not a de Polignac number, because 111001220021 - 2¹⁸ = 111000957877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111001219984 and 111001220011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111001220221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55500610010 + 55500610011.

It is an arithmetic number, because the mean of its divisors is an integer number (55500610011).

Almost surely, 2^111001220021 is an apocalyptic number.

It is an amenable number.

111001220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

111001220021 is an equidigital number, since it uses as much as digits as its factorization.

111001220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 111001220021 its reverse (120022100111), we get a palindrome (231023320132).

The spelling of 111001220021 in words is "one hundred eleven billion, one million, two hundred twenty thousand, twenty-one".