278879647 has 4 divisors (see below), whose sum is σ = 278963776. Its totient is φ = 278795520.

The previous prime is 278879621. The next prime is 278879687. The reversal of 278879647 is 746978872.

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 278879647 - 2⁷ = 278879519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 278879591 and 278879600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278879687) 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, 36879 + ... + 43792.

It is an arithmetic number, because the mean of its divisors is an integer number (69740944).

Almost surely, 2^278879647 is an apocalyptic number.

278879647 is a deficient number, since it is larger than the sum of its proper divisors (84129).

278879647 is an equidigital number, since it uses as much as digits as its factorization.

278879647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84128.

The product of its digits is 9483264, while the sum is 58.

The square root of 278879647 is about 16699.6900270634. The cubic root of 278879647 is about 653.3395363900.

The spelling of 278879647 in words is "two hundred seventy-eight million, eight hundred seventy-nine thousand, six hundred forty-seven".