281978 has 4 divisors (see below), whose sum is σ = 422970. Its totient is φ = 140988.

The previous prime is 281971. The next prime is 281989. The reversal of 281978 is 879182.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 247009 + 34969 = 497^2 + 187^2 .

It is not an unprimeable number, because it can be changed into a prime (281971) by changing a digit.

281978 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70493 + ... + 70496.

2²⁸¹⁹⁷⁸ is an apocalyptic number.

281978 is a deficient number, since it is larger than the sum of its proper divisors (140992).

281978 is a wasteful number, since it uses less digits than its factorization.

281978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140991.

The product of its digits is 8064, while the sum is 35.

The square root of 281978 is about 531.0160072917. The cubic root of 281978 is about 65.5750165125.

The spelling of 281978 in words is "two hundred eighty-one thousand, nine hundred seventy-eight".