278812 has 12 divisors (see below), whose sum is σ = 499576. Its totient is φ = 136080.

The previous prime is 278809. The next prime is 278813. The reversal of 278812 is 218872.

It is a super-2 number, since 2×278812² = 155472262688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278813) 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, 639 + ... + 982.

2²⁷⁸⁸¹² is an apocalyptic number.

It is an amenable number.

278812 is a deficient number, since it is larger than the sum of its proper divisors (220764).

278812 is a wasteful number, since it uses less digits than its factorization.

278812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1668 (or 1666 counting only the distinct ones).

The product of its digits is 1792, while the sum is 28.

The square root of 278812 is about 528.0265144858. The cubic root of 278812 is about 65.3286705914.

Subtracting from 278812 its sum of digits (28), we obtain a square (278784 = 528²).

The spelling of 278812 in words is "two hundred seventy-eight thousand, eight hundred twelve".