381643919 has 4 divisors (see below), whose sum is σ = 388112520. Its totient is φ = 375175320.

The previous prime is 381643909. The next prime is 381643939. The reversal of 381643919 is 919346183.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 381643919 - 2²⁴ = 364866703 is a prime.

It is a super-2 number, since 2×381643919² = 291304161819357122, 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 381643919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381643909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3234212 + ... + 3234329.

It is an arithmetic number, because the mean of its divisors is an integer number (97028130).

Almost surely, 2^381643919 is an apocalyptic number.

381643919 is a deficient number, since it is larger than the sum of its proper divisors (6468601).

381643919 is an equidigital number, since it uses as much as digits as its factorization.

381643919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6468600.

The product of its digits is 139968, while the sum is 44.

The square root of 381643919 is about 19535.7088174450. The cubic root of 381643919 is about 725.3586297047.

The spelling of 381643919 in words is "three hundred eighty-one million, six hundred forty-three thousand, nine hundred nineteen".