424100021 has 2 divisors, whose sum is σ = 424100022. Its totient is φ = 424100020.

The previous prime is 424099987. The next prime is 424100051. The reversal of 424100021 is 120001424.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 418407025 + 5692996 = 20455^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 424100021 - 2¹⁸ = 423837877 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 424099969 and 424100005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (424100051) 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, 212050010 + 212050011.

It is an arithmetic number, because the mean of its divisors is an integer number (212050011).

Almost surely, 2^424100021 is an apocalyptic number.

It is an amenable number.

424100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

424100021 is an equidigital number, since it uses as much as digits as its factorization.

424100021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 424100021 is about 20593.6888633387. The cubic root of 424100021 is about 751.3162196993.

Adding to 424100021 its reverse (120001424), we get a palindrome (544101445).

The spelling of 424100021 in words is "four hundred twenty-four million, one hundred thousand, twenty-one".