381631 has 2 divisors, whose sum is σ = 381632. Its totient is φ = 381630.

The previous prime is 381629. The next prime is 381637. The reversal of 381631 is 136183.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 381631 - 2¹ = 381629 is a prime.

It is a super-2 number, since 2×381631² = 291284440322, which contains 22 as substring.

Together with 381629, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190815 + 190816.

It is an arithmetic number, because the mean of its divisors is an integer number (190816).

2³⁸¹⁶³¹ is an apocalyptic number.

381631 is a deficient number, since it is larger than the sum of its proper divisors (1).

381631 is an equidigital number, since it uses as much as digits as its factorization.

381631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 22.

The square root of 381631 is about 617.7628995011. The cubic root of 381631 is about 72.5350444925.

The spelling of 381631 in words is "three hundred eighty-one thousand, six hundred thirty-one".