421093921 has 2 divisors, whose sum is σ = 421093922. Its totient is φ = 421093920.

The previous prime is 421093909. The next prime is 421093931. The reversal of 421093921 is 129390124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 351187600 + 69906321 = 18740^2 + 8361^2 .

It is a cyclic number.

It is not a de Polignac number, because 421093921 - 2⁵ = 421093889 is a prime.

It is not a weakly prime, because it can be changed into another prime (421093931) 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, 210546960 + 210546961.

It is an arithmetic number, because the mean of its divisors is an integer number (210546961).

Almost surely, 2^421093921 is an apocalyptic number.

It is an amenable number.

421093921 is a deficient number, since it is larger than the sum of its proper divisors (1).

421093921 is an equidigital number, since it uses as much as digits as its factorization.

421093921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 421093921 is about 20520.5731157782. The cubic root of 421093921 is about 749.5368524217.

The spelling of 421093921 in words is "four hundred twenty-one million, ninety-three thousand, nine hundred twenty-one".