421718399 has 2 divisors, whose sum is σ = 421718400. Its totient is φ = 421718398.

The previous prime is 421718383. The next prime is 421718419. The reversal of 421718399 is 993817124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 421718399 - 2⁴ = 421718383 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421718309) 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, 210859199 + 210859200.

It is an arithmetic number, because the mean of its divisors is an integer number (210859200).

Almost surely, 2^421718399 is an apocalyptic number.

421718399 is a deficient number, since it is larger than the sum of its proper divisors (1).

421718399 is an equidigital number, since it uses as much as digits as its factorization.

421718399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 44.

The square root of 421718399 is about 20535.7833792626. The cubic root of 421718399 is about 749.9071879224.

The spelling of 421718399 in words is "four hundred twenty-one million, seven hundred eighteen thousand, three hundred ninety-nine".