278397 has 20 divisors (see below), whose sum is σ = 476256. Its totient is φ = 158760.

The previous prime is 278393. The next prime is 278413. The reversal of 278397 is 793872.

It is not a de Polignac number, because 278397 - 2² = 278393 is a prime.

It is an Ulam number.

278397 is a lucky number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 322 + ... + 812.

2²⁷⁸³⁹⁷ is an apocalyptic number.

278397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

278397 is a deficient number, since it is larger than the sum of its proper divisors (197859).

278397 is an equidigital number, since it uses as much as digits as its factorization.

278397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510 (or 501 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 278397 is about 527.6333954556. The cubic root of 278397 is about 65.2962414984.

The spelling of 278397 in words is "two hundred seventy-eight thousand, three hundred ninety-seven".