378781 has 4 divisors (see below), whose sum is σ = 407932. Its totient is φ = 349632.

The previous prime is 378779. The next prime is 378793. The reversal of 378781 is 187873.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187873 = 7 ⋅26839.

It can be written as a sum of positive squares in 2 ways, for example, as 210681 + 168100 = 459^2 + 410^2 .

It is a cyclic number.

It is not a de Polignac number, because 378781 - 2¹ = 378779 is a prime.

It is a super-2 number, since 2×378781² = 286950091922, 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 (378761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14556 + ... + 14581.

It is an arithmetic number, because the mean of its divisors is an integer number (101983).

2³⁷⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

378781 is a deficient number, since it is larger than the sum of its proper divisors (29151).

378781 is a wasteful number, since it uses less digits than its factorization.

378781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29150.

The product of its digits is 9408, while the sum is 34.

The square root of 378781 is about 615.4518665176. The cubic root of 378781 is about 72.3540305236.

The spelling of 378781 in words is "three hundred seventy-eight thousand, seven hundred eighty-one".