391278249 has 16 divisors (see below), whose sum is σ = 598371840. Its totient is φ = 252437040.

The previous prime is 391278247. The next prime is 391278257. The reversal of 391278249 is 942872193.

It is not a de Polignac number, because 391278249 - 2¹ = 391278247 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (391278247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232902 + ... + 234575.

It is an arithmetic number, because the mean of its divisors is an integer number (37398240).

Almost surely, 2^391278249 is an apocalyptic number.

It is an amenable number.

391278249 is a deficient number, since it is larger than the sum of its proper divisors (207093591).

391278249 is a wasteful number, since it uses less digits than its factorization.

391278249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467517 (or 467511 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 391278249 is about 19780.7545103821. The cubic root of 391278249 is about 731.4116981011.

The spelling of 391278249 in words is "three hundred ninety-one million, two hundred seventy-eight thousand, two hundred forty-nine".