423009991 has 2 divisors, whose sum is σ = 423009992. Its totient is φ = 423009990.

The previous prime is 423009959. The next prime is 423010009. The reversal of 423009991 is 199900324.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 423009991 - 2⁵ = 423009959 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 423009991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (423009941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 211504995 + 211504996.

It is an arithmetic number, because the mean of its divisors is an integer number (211504996).

Almost surely, 2^423009991 is an apocalyptic number.

423009991 is a deficient number, since it is larger than the sum of its proper divisors (1).

423009991 is an equidigital number, since it uses as much as digits as its factorization.

423009991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 423009991 is about 20567.2066892906. The cubic root of 423009991 is about 750.6719849943.

The spelling of 423009991 in words is "four hundred twenty-three million, nine thousand, nine hundred ninety-one".