391278 has 8 divisors (see below), whose sum is σ = 782568. Its totient is φ = 130424.

The previous prime is 391273. The next prime is 391283. The reversal of 391278 is 872193.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (391273) and next prime (391283).

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

391278 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391273) by changing a digit.

391278 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32601 + ... + 32612.

It is an arithmetic number, because the mean of its divisors is an integer number (97821).

2³⁹¹²⁷⁸ is an apocalyptic number.

391278 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391278 is a wasteful number, since it uses less digits than its factorization.

391278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65218.

The product of its digits is 3024, while the sum is 30.

The square root of 391278 is about 625.5221818609. The cubic root of 391278 is about 73.1411542950.

The spelling of 391278 in words is "three hundred ninety-one thousand, two hundred seventy-eight".