278394139 has 4 divisors (see below), whose sum is σ = 290498256. Its totient is φ = 266290024.

The previous prime is 278394121. The next prime is 278394157. The reversal of 278394139 is 931493872.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (278394121) and next prime (278394157).

It is a cyclic number.

It is not a de Polignac number, because 278394139 - 2¹⁵ = 278361371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278394119) 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, 6052024 + ... + 6052069.

It is an arithmetic number, because the mean of its divisors is an integer number (72624564).

Almost surely, 2^278394139 is an apocalyptic number.

278394139 is a deficient number, since it is larger than the sum of its proper divisors (12104117).

278394139 is a wasteful number, since it uses less digits than its factorization.

278394139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12104116.

The product of its digits is 326592, while the sum is 46.

The square root of 278394139 is about 16685.1472573664. The cubic root of 278394139 is about 652.9601782119.

The spelling of 278394139 in words is "two hundred seventy-eight million, three hundred ninety-four thousand, one hundred thirty-nine".