381658 has 4 divisors (see below), whose sum is σ = 572490. Its totient is φ = 190828.

The previous prime is 381637. The next prime is 381659. The reversal of 381658 is 856183.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 856183 = 311 ⋅2753.

It can be written as a sum of positive squares in only one way, i.e., 257049 + 124609 = 507^2 + 353^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

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 as a sum of consecutive naturals, namely, 95413 + ... + 95416.

2³⁸¹⁶⁵⁸ is an apocalyptic number.

381658 is a deficient number, since it is larger than the sum of its proper divisors (190832).

381658 is a wasteful number, since it uses less digits than its factorization.

381658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190831.

The product of its digits is 5760, while the sum is 31.

The square root of 381658 is about 617.7847521589. The cubic root of 381658 is about 72.5367550454.

The spelling of 381658 in words is "three hundred eighty-one thousand, six hundred fifty-eight".