421621 has 2 divisors, whose sum is σ = 421622. Its totient is φ = 421620.

The previous prime is 421609. The next prime is 421633. The reversal of 421621 is 126124.

It is a balanced prime because it is at equal distance from previous prime (421609) and next prime (421633).

It can be written as a sum of positive squares in only one way, i.e., 324900 + 96721 = 570^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 421621 - 2⁷ = 421493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 421595 and 421604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421661) 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, 210810 + 210811.

It is an arithmetic number, because the mean of its divisors is an integer number (210811).

2⁴²¹⁶²¹ is an apocalyptic number.

It is an amenable number.

421621 is a deficient number, since it is larger than the sum of its proper divisors (1).

421621 is an equidigital number, since it uses as much as digits as its factorization.

421621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 16.

The square root of 421621 is about 649.3234941075. The cubic root of 421621 is about 74.9849451264.

Adding to 421621 its reverse (126124), we get a palindrome (547745).

The spelling of 421621 in words is "four hundred twenty-one thousand, six hundred twenty-one".