381643655 has 4 divisors (see below), whose sum is σ = 457972392. Its totient is φ = 305314920.

The previous prime is 381643651. The next prime is 381643679. The reversal of 381643655 is 556346183.

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

It is not a de Polignac number, because 381643655 - 2² = 381643651 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 (381643651) 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, 38164361 + ... + 38164370.

It is an arithmetic number, because the mean of its divisors is an integer number (114493098).

Almost surely, 2^381643655 is an apocalyptic number.

381643655 is a deficient number, since it is larger than the sum of its proper divisors (76328737).

381643655 is an equidigital number, since it uses as much as digits as its factorization.

381643655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76328736.

The product of its digits is 259200, while the sum is 41.

The square root of 381643655 is about 19535.7020605864. The cubic root of 381643655 is about 725.3584624505.

The spelling of 381643655 in words is "three hundred eighty-one million, six hundred forty-three thousand, six hundred fifty-five".