278920393 has 8 divisors (see below), whose sum is σ = 289680840. Its totient is φ = 268329600.

The previous prime is 278920381. The next prime is 278920459. The reversal of 278920393 is 393029872.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25887744 + 253032649 = 5088^2 + 15907^2 .

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 278920393 - 2¹³ = 278912201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278920303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39058 + ... + 45643.

It is an arithmetic number, because the mean of its divisors is an integer number (36210105).

Almost surely, 2^278920393 is an apocalyptic number.

It is an amenable number.

278920393 is a deficient number, since it is larger than the sum of its proper divisors (10760447).

278920393 is an equidigital number, since it uses as much as digits as its factorization.

278920393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84827.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 278920393 is about 16700.9099452694. The cubic root of 278920393 is about 653.3713537907.

The spelling of 278920393 in words is "two hundred seventy-eight million, nine hundred twenty thousand, three hundred ninety-three".