278678 has 4 divisors (see below), whose sum is σ = 418020. Its totient is φ = 139338.

The previous prime is 278671. The next prime is 278687. The reversal of 278678 is 876872.

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

It is a super-2 number, since 2×278678² = 155322855368, which contains 22 as substring.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278671) by changing a digit.

278678 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, 69668 + ... + 69671.

It is an arithmetic number, because the mean of its divisors is an integer number (104505).

2²⁷⁸⁶⁷⁸ is an apocalyptic number.

278678 is a deficient number, since it is larger than the sum of its proper divisors (139342).

278678 is a wasteful number, since it uses less digits than its factorization.

278678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139341.

The product of its digits is 37632, while the sum is 38.

The square root of 278678 is about 527.8996116687. The cubic root of 278678 is about 65.3182030306.

The spelling of 278678 in words is "two hundred seventy-eight thousand, six hundred seventy-eight".