381657 has 4 divisors (see below), whose sum is σ = 508880. Its totient is φ = 254436.

The previous prime is 381637. The next prime is 381659. The reversal of 381657 is 756183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 381657 - 2⁷ = 381529 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (381659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63607 + ... + 63612.

It is an arithmetic number, because the mean of its divisors is an integer number (127220).

2³⁸¹⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

381657 is a deficient number, since it is larger than the sum of its proper divisors (127223).

381657 is a wasteful number, since it uses less digits than its factorization.

381657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127222.

The product of its digits is 5040, while the sum is 30.

The square root of 381657 is about 617.7839428150. The cubic root of 381657 is about 72.5366916930.

The spelling of 381657 in words is "three hundred eighty-one thousand, six hundred fifty-seven".