7278239 has 2 divisors, whose sum is σ = 7278240. Its totient is φ = 7278238.

The previous prime is 7278209. The next prime is 7278241. The reversal of 7278239 is 9328727.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 7278239 - 2¹⁶ = 7212703 is a prime.

It is a super-2 number, since 2×7278239² = 105945525882242, which contains 22 as substring.

Together with 7278241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7278209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3639119 + 3639120.

It is an arithmetic number, because the mean of its divisors is an integer number (3639120).

Almost surely, 2^7278239 is an apocalyptic number.

7278239 is a deficient number, since it is larger than the sum of its proper divisors (1).

7278239 is an equidigital number, since it uses as much as digits as its factorization.

7278239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 38.

The square root of 7278239 is about 2697.8211578976. The cubic root of 7278239 is about 193.7947931121.

The spelling of 7278239 in words is "seven million, two hundred seventy-eight thousand, two hundred thirty-nine".