278928257 has 8 divisors (see below), whose sum is σ = 284740992. Its totient is φ = 273168000.

The previous prime is 278928233. The next prime is 278928263. The reversal of 278928257 is 752829872.

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

It is a cyclic number.

It is not a de Polignac number, because 278928257 - 2⁶ = 278928193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278928217) 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, 2288 + ... + 23729.

It is an arithmetic number, because the mean of its divisors is an integer number (35592624).

Almost surely, 2^278928257 is an apocalyptic number.

It is an amenable number.

278928257 is a deficient number, since it is larger than the sum of its proper divisors (5812735).

278928257 is a wasteful number, since it uses less digits than its factorization.

278928257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26239.

The product of its digits is 1128960, while the sum is 50.

The square root of 278928257 is about 16701.1453798834. The cubic root of 278928257 is about 653.3774942094.

The spelling of 278928257 in words is "two hundred seventy-eight million, nine hundred twenty-eight thousand, two hundred fifty-seven".