390978 has 48 divisors (see below), whose sum is σ = 1010880. Its totient is φ = 106848.

The previous prime is 390967. The next prime is 390989. The reversal of 390978 is 879093.

It is an interprime number because it is at equal distance from previous prime (390967) and next prime (390989).

It is an unprimeable number.

390978 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3601 + ... + 3707.

It is an arithmetic number, because the mean of its divisors is an integer number (21060).

2³⁹⁰⁹⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 390978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (505440).

390978 is an abundant number, since it is smaller than the sum of its proper divisors (619902).

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

390978 is a wasteful number, since it uses less digits than its factorization.

390978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 390978 is about 625.2823362290. The cubic root of 390978 is about 73.1224566286.

The spelling of 390978 in words is "three hundred ninety thousand, nine hundred seventy-eight".