423401021 has 2 divisors, whose sum is σ = 423401022. Its totient is φ = 423401020.

The previous prime is 423401009. The next prime is 423401029. The reversal of 423401021 is 120104324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 415588996 + 7812025 = 20386^2 + 2795^2 .

It is a cyclic number.

It is not a de Polignac number, because 423401021 - 2¹⁰ = 423399997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (423401029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 211700510 + 211700511.

It is an arithmetic number, because the mean of its divisors is an integer number (211700511).

Almost surely, 2^423401021 is an apocalyptic number.

It is an amenable number.

423401021 is a deficient number, since it is larger than the sum of its proper divisors (1).

423401021 is an equidigital number, since it uses as much as digits as its factorization.

423401021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 423401021 is about 20576.7106457762. The cubic root of 423401021 is about 750.9032205609.

Adding to 423401021 its reverse (120104324), we get a palindrome (543505345).

The spelling of 423401021 in words is "four hundred twenty-three million, four hundred one thousand, twenty-one".