384336721 has 2 divisors, whose sum is σ = 384336722. Its totient is φ = 384336720.

The previous prime is 384336683. The next prime is 384336727. The reversal of 384336721 is 127633483.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 320016321 + 64320400 = 17889^2 + 8020^2 .

It is an emirp because it is prime and its reverse (127633483) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 384336721 - 2²⁷ = 250118993 is a prime.

It is not a weakly prime, because it can be changed into another prime (384336727) 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, 192168360 + 192168361.

It is an arithmetic number, because the mean of its divisors is an integer number (192168361).

Almost surely, 2^384336721 is an apocalyptic number.

It is an amenable number.

384336721 is a deficient number, since it is larger than the sum of its proper divisors (1).

384336721 is an equidigital number, since it uses as much as digits as its factorization.

384336721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 37.

The square root of 384336721 is about 19604.5076704313. The cubic root of 384336721 is about 727.0606273785.

It can be divided in two parts, 38433 and 6721, that added together give a palindrome (45154).

The spelling of 384336721 in words is "three hundred eighty-four million, three hundred thirty-six thousand, seven hundred twenty-one".