381981 has 8 divisors (see below), whose sum is σ = 513184. Its totient is φ = 252720.

The previous prime is 381977. The next prime is 381989. The reversal of 381981 is 189183.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 381981 - 2² = 381977 is a prime.

It is a super-2 number, since 2×381981² = 291818968722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 66 + ... + 876.

It is an arithmetic number, because the mean of its divisors is an integer number (64148).

2³⁸¹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

381981 is a deficient number, since it is larger than the sum of its proper divisors (131203).

381981 is a wasteful number, since it uses less digits than its factorization.

381981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 971.

The product of its digits is 1728, while the sum is 30.

The square root of 381981 is about 618.0461147843. The cubic root of 381981 is about 72.5572120737.

The spelling of 381981 in words is "three hundred eighty-one thousand, nine hundred eighty-one".