390816738 has 80 divisors (see below), whose sum is σ = 992819520. Its totient is φ = 113910624.

The previous prime is 390816661. The next prime is 390816739. The reversal of 390816738 is 837618093.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 390816693 and 390816702.

It is not an unprimeable number, because it can be changed into a prime (390816739) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 35131 + ... + 44897.

It is an arithmetic number, because the mean of its divisors is an integer number (12410244).

Almost surely, 2^390816738 is an apocalyptic number.

390816738 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 390816738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (496409760).

390816738 is an abundant number, since it is smaller than the sum of its proper divisors (602002782).

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

390816738 is a wasteful number, since it uses less digits than its factorization.

390816738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9813 (or 9804 counting only the distinct ones).

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

The square root of 390816738 is about 19769.0854113183. The cubic root of 390816738 is about 731.1240193228.

The spelling of 390816738 in words is "three hundred ninety million, eight hundred sixteen thousand, seven hundred thirty-eight".