390864840 has 128 divisors (see below), whose sum is σ = 1208908800. Its totient is φ = 101041920.

The previous prime is 390864839. The next prime is 390864847. The reversal of 390864840 is 48468093.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 390864792 and 390864801.

It is not an unprimeable number, because it can be changed into a prime (390864847) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1088581 + ... + 1088939.

It is an arithmetic number, because the mean of its divisors is an integer number (9444600).

Almost surely, 2^390864840 is an apocalyptic number.

390864840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 390864840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (604454400).

390864840 is an abundant number, since it is smaller than the sum of its proper divisors (818043960).

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

390864840 is a wasteful number, since it uses less digits than its factorization.

390864840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 390864840 is about 19770.3019703797. The cubic root of 390864840 is about 731.1540138457.

The spelling of 390864840 in words is "three hundred ninety million, eight hundred sixty-four thousand, eight hundred forty".