278642423 has 2 divisors, whose sum is σ = 278642424. Its totient is φ = 278642422.

The previous prime is 278642389. The next prime is 278642459. The reversal of 278642423 is 324246872.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-278642423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278642473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139321211 + 139321212.

It is an arithmetic number, because the mean of its divisors is an integer number (139321212).

Almost surely, 2^278642423 is an apocalyptic number.

278642423 is a deficient number, since it is larger than the sum of its proper divisors (1).

278642423 is an equidigital number, since it uses as much as digits as its factorization.

278642423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 38.

The square root of 278642423 is about 16692.5858691816. The cubic root of 278642423 is about 653.1542332954.

The spelling of 278642423 in words is "two hundred seventy-eight million, six hundred forty-two thousand, four hundred twenty-three".