381987 has 6 divisors (see below), whose sum is σ = 551772. Its totient is φ = 254652.

The previous prime is 381977. The next prime is 381989. The reversal of 381987 is 789183.

It is not a de Polignac number, because 381987 - 2⁷ = 381859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (381989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21213 + ... + 21230.

It is an arithmetic number, because the mean of its divisors is an integer number (91962).

2³⁸¹⁹⁸⁷ is an apocalyptic number.

381987 is a deficient number, since it is larger than the sum of its proper divisors (169785).

381987 is a wasteful number, since it uses less digits than its factorization.

381987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42449 (or 42446 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 381987 is about 618.0509687720. The cubic root of 381987 is about 72.5575919713.

It can be divided in two parts, 38 and 1987, that added together give a square (2025 = 45²).

The spelling of 381987 in words is "three hundred eighty-one thousand, nine hundred eighty-seven".