278398343 has 4 divisors (see below), whose sum is σ = 284321760. Its totient is φ = 272474928.

The previous prime is 278398301. The next prime is 278398349. The reversal of 278398343 is 343893872.

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

It is a cyclic number.

It is not a de Polignac number, because 278398343 - 2¹² = 278394247 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 5923369 = 278398343 / (2 + 7 + 8 + 3 + 9 + 8 + 3 + 4 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278398349) 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, 2961638 + ... + 2961731.

It is an arithmetic number, because the mean of its divisors is an integer number (71080440).

Almost surely, 2^278398343 is an apocalyptic number.

278398343 is a deficient number, since it is larger than the sum of its proper divisors (5923417).

278398343 is an equidigital number, since it uses as much as digits as its factorization.

278398343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5923416.

The product of its digits is 870912, while the sum is 47.

The square root of 278398343 is about 16685.2732371993. The cubic root of 278398343 is about 652.9634649559.

The spelling of 278398343 in words is "two hundred seventy-eight million, three hundred ninety-eight thousand, three hundred forty-three".