421411021 has 2 divisors, whose sum is σ = 421411022. Its totient is φ = 421411020.

The previous prime is 421410967. The next prime is 421411031. The reversal of 421411021 is 120114124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 232898121 + 188512900 = 15261^2 + 13730^2 .

It is a cyclic number.

It is not a de Polignac number, because 421411021 - 2¹¹ = 421408973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 421410986 and 421411004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421411031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210705510 + 210705511.

It is an arithmetic number, because the mean of its divisors is an integer number (210705511).

Almost surely, 2^421411021 is an apocalyptic number.

It is an amenable number.

421411021 is a deficient number, since it is larger than the sum of its proper divisors (1).

421411021 is an equidigital number, since it uses as much as digits as its factorization.

421411021 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 16.

The square root of 421411021 is about 20528.2980541495. The cubic root of 421411021 is about 749.7249486228.

Adding to 421411021 its reverse (120114124), we get a palindrome (541525145).

The spelling of 421411021 in words is "four hundred twenty-one million, four hundred eleven thousand, twenty-one".