278661317 has 8 divisors (see below), whose sum is σ = 304780320. Its totient is φ = 252673360.

The previous prime is 278661283. The next prime is 278661329. The reversal of 278661317 is 713166872.

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 278661317 - 2¹⁰ = 278660293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278661347) 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, 28283 + ... + 36840.

It is an arithmetic number, because the mean of its divisors is an integer number (38097540).

Almost surely, 2^278661317 is an apocalyptic number.

It is an amenable number.

278661317 is a deficient number, since it is larger than the sum of its proper divisors (26119003).

278661317 is a wasteful number, since it uses less digits than its factorization.

278661317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65523.

The product of its digits is 84672, while the sum is 41.

The square root of 278661317 is about 16693.1517994656. The cubic root of 278661317 is about 653.1689958443.

The spelling of 278661317 in words is "two hundred seventy-eight million, six hundred sixty-one thousand, three hundred seventeen".