278676823 has 2 divisors, whose sum is σ = 278676824. Its totient is φ = 278676822.

The previous prime is 278676817. The next prime is 278676833. The reversal of 278676823 is 328676872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278676823 - 2¹³ = 278668631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278676803) 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 as a sum of consecutive naturals, namely, 139338411 + 139338412.

It is an arithmetic number, because the mean of its divisors is an integer number (139338412).

Almost surely, 2^278676823 is an apocalyptic number.

278676823 is a deficient number, since it is larger than the sum of its proper divisors (1).

278676823 is an equidigital number, since it uses as much as digits as its factorization.

278676823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 49.

The square root of 278676823 is about 16693.6162349564. The cubic root of 278676823 is about 653.1811107307.

Adding to 278676823 its sum of digits (49), we get a palindrome (278676872).

The spelling of 278676823 in words is "two hundred seventy-eight million, six hundred seventy-six thousand, eight hundred twenty-three".