421565999 has 2 divisors, whose sum is σ = 421566000. Its totient is φ = 421565998.

The previous prime is 421565981. The next prime is 421566031. The reversal of 421565999 is 999565124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 421565999 - 2⁸ = 421565743 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 (421565909) 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, 210782999 + 210783000.

It is an arithmetic number, because the mean of its divisors is an integer number (210783000).

Almost surely, 2^421565999 is an apocalyptic number.

421565999 is a deficient number, since it is larger than the sum of its proper divisors (1).

421565999 is an equidigital number, since it uses as much as digits as its factorization.

421565999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 874800, while the sum is 50.

The square root of 421565999 is about 20532.0724477584. The cubic root of 421565999 is about 749.8168435716.

The spelling of 421565999 in words is "four hundred twenty-one million, five hundred sixty-five thousand, nine hundred ninety-nine".