423541661 has 2 divisors, whose sum is σ = 423541662. Its totient is φ = 423541660.

The previous prime is 423541637. The next prime is 423541663. The reversal of 423541661 is 166145324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 385336900 + 38204761 = 19630^2 + 6181^2 .

It is a cyclic number.

It is not a de Polignac number, because 423541661 - 2¹⁸ = 423279517 is a prime.

It is a Sophie Germain prime.

Together with 423541663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (423541663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 211770830 + 211770831.

It is an arithmetic number, because the mean of its divisors is an integer number (211770831).

Almost surely, 2^423541661 is an apocalyptic number.

It is an amenable number.

423541661 is a deficient number, since it is larger than the sum of its proper divisors (1).

423541661 is an equidigital number, since it uses as much as digits as its factorization.

423541661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The square root of 423541661 is about 20580.1278178732. The cubic root of 423541661 is about 750.9863532041.

Adding to 423541661 its reverse (166145324), we get a palindrome (589686985).

The spelling of 423541661 in words is "four hundred twenty-three million, five hundred forty-one thousand, six hundred sixty-one".