381918329 has 8 divisors (see below), whose sum is σ = 422413320. Its totient is φ = 343011456.

The previous prime is 381918319. The next prime is 381918331. The reversal of 381918329 is 923819183.

It can be written as a sum of positive squares in 4 ways, for example, as 32228329 + 349690000 = 5677^2 + 18700^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-381918329 is a prime.

It is a super-2 number, since 2×381918329² = 291723220052304482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 381918329.

It is not an unprimeable number, because it can be changed into a prime (381918319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396524 + ... + 397485.

It is an arithmetic number, because the mean of its divisors is an integer number (52801665).

Almost surely, 2^381918329 is an apocalyptic number.

It is an amenable number.

381918329 is a deficient number, since it is larger than the sum of its proper divisors (40494991).

381918329 is a wasteful number, since it uses less digits than its factorization.

381918329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794059.

The product of its digits is 93312, while the sum is 44.

The square root of 381918329 is about 19542.7308480673. The cubic root of 381918329 is about 725.5324374216.

The spelling of 381918329 in words is "three hundred eighty-one million, nine hundred eighteen thousand, three hundred twenty-nine".