390387840 has 128 divisors (see below), whose sum is σ = 1254942720. Its totient is φ = 103219200.

The previous prime is 390387797. The next prime is 390387863. The reversal of 390387840 is 48783093.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 390387792 and 390387801.

It is an unprimeable 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 15 ways as a sum of consecutive naturals, for example, 243040 + ... + 244640.

It is an arithmetic number, because the mean of its divisors is an integer number (9804240).

Almost surely, 2^390387840 is an apocalyptic number.

390387840 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 390387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (627471360).

390387840 is an abundant number, since it is smaller than the sum of its proper divisors (864554880).

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

390387840 is a wasteful number, since it uses less digits than its factorization.

390387840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1750 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 390387840 is about 19758.2347389639. The cubic root of 390387840 is about 730.8564664606.

The spelling of 390387840 in words is "three hundred ninety million, three hundred eighty-seven thousand, eight hundred forty".