381651 has 4 divisors (see below), whose sum is σ = 508872. Its totient is φ = 254432.

The previous prime is 381637. The next prime is 381659. The reversal of 381651 is 156183.

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 381651 - 2⁷ = 381523 is a prime.

It is a D-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, 63606 + ... + 63611.

It is an arithmetic number, because the mean of its divisors is an integer number (127218).

2³⁸¹⁶⁵¹ is an apocalyptic number.

381651 is a deficient number, since it is larger than the sum of its proper divisors (127221).

381651 is a wasteful number, since it uses less digits than its factorization.

381651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127220.

The product of its digits is 720, while the sum is 24.

The square root of 381651 is about 617.7790867292. The cubic root of 381651 is about 72.5363115765.

The spelling of 381651 in words is "three hundred eighty-one thousand, six hundred fifty-one".