105404021 has 2 divisors, whose sum is σ = 105404022. Its totient is φ = 105404020.

The previous prime is 105404017. The next prime is 105404023. The reversal of 105404021 is 120404501.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100781521 + 4622500 = 10039^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 105404021 - 2² = 105404017 is a prime.

It is a super-2 number, since 2×105404021² = 22220015285936882, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 105404023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (105404023) 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 as a sum of consecutive naturals, namely, 52702010 + 52702011.

It is an arithmetic number, because the mean of its divisors is an integer number (52702011).

Almost surely, 2^105404021 is an apocalyptic number.

It is an amenable number.

105404021 is a deficient number, since it is larger than the sum of its proper divisors (1).

105404021 is an equidigital number, since it uses as much as digits as its factorization.

105404021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 105404021 is about 10266.6460443516. The cubic root of 105404021 is about 472.3737180138.

Adding to 105404021 its reverse (120404501), we get a palindrome (225808522).

The spelling of 105404021 in words is "one hundred five million, four hundred four thousand, twenty-one".