384099721 has 4 divisors (see below), whose sum is σ = 384810244. Its totient is φ = 383389200.

The previous prime is 384099713. The next prime is 384099731. The reversal of 384099721 is 127990483.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127990483 = 1973 ⋅64871.

It can be written as a sum of positive squares in 2 ways, for example, as 60279696 + 323820025 = 7764^2 + 17995^2 .

It is a cyclic number.

It is not a de Polignac number, because 384099721 - 2³ = 384099713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (384099731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 354450 + ... + 355531.

It is an arithmetic number, because the mean of its divisors is an integer number (96202561).

Almost surely, 2^384099721 is an apocalyptic number.

It is an amenable number.

384099721 is a deficient number, since it is larger than the sum of its proper divisors (710523).

384099721 is an equidigital number, since it uses as much as digits as its factorization.

384099721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710522.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 384099721 is about 19598.4622100817. The cubic root of 384099721 is about 726.9111501187.

The spelling of 384099721 in words is "three hundred eighty-four million, ninety-nine thousand, seven hundred twenty-one".