423989 has 2 divisors, whose sum is σ = 423990. Its totient is φ = 423988.

The previous prime is 423977. The next prime is 423991. The reversal of 423989 is 989324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 339889 + 84100 = 583^2 + 290^2 .

It is a cyclic number.

It is not a de Polignac number, because 423989 - 2¹² = 419893 is a prime.

Together with 423991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (423949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 211994 + 211995.

It is an arithmetic number, because the mean of its divisors is an integer number (211995).

2⁴²³⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

423989 is a deficient number, since it is larger than the sum of its proper divisors (1).

423989 is an equidigital number, since it uses as much as digits as its factorization.

423989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 35.

The square root of 423989 is about 651.1443772313. The cubic root of 423989 is about 75.1250654067.

The spelling of 423989 in words is "four hundred twenty-three thousand, nine hundred eighty-nine".