278928993 has 8 divisors (see below), whose sum is σ = 425034688. Its totient is φ = 159387984.

The previous prime is 278928961. The next prime is 278929009. The reversal of 278928993 is 399829872.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 278928993 - 2⁵ = 278928961 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (278928943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6641146 + ... + 6641187.

It is an arithmetic number, because the mean of its divisors is an integer number (53129336).

Almost surely, 2^278928993 is an apocalyptic number.

It is an amenable number.

278928993 is a deficient number, since it is larger than the sum of its proper divisors (146105695).

278928993 is a wasteful number, since it uses less digits than its factorization.

278928993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13282343.

The product of its digits is 3919104, while the sum is 57.

The square root of 278928993 is about 16701.1674142857. The cubic root of 278928993 is about 653.3780688917.

The spelling of 278928993 in words is "two hundred seventy-eight million, nine hundred twenty-eight thousand, nine hundred ninety-three".