381728357 has 4 divisors (see below), whose sum is σ = 381771180. Its totient is φ = 381685536.

The previous prime is 381728323. The next prime is 381728359. The reversal of 381728357 is 753827183.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 753827183 = 151 ⋅4992233.

It can be written as a sum of positive squares in 2 ways, for example, as 76492516 + 305235841 = 8746^2 + 17471^2 .

It is a cyclic number.

It is not a de Polignac number, because 381728357 - 2¹⁴ = 381711973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381728359) 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, 2432 + ... + 27737.

It is an arithmetic number, because the mean of its divisors is an integer number (95442795).

Almost surely, 2^381728357 is an apocalyptic number.

It is an amenable number.

381728357 is a deficient number, since it is larger than the sum of its proper divisors (42823).

381728357 is a wasteful number, since it uses less digits than its factorization.

381728357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42822.

The product of its digits is 282240, while the sum is 44.

The square root of 381728357 is about 19537.8698173573. The cubic root of 381728357 is about 725.4121205047.

The spelling of 381728357 in words is "three hundred eighty-one million, seven hundred twenty-eight thousand, three hundred fifty-seven".