388440640 has 112 divisors (see below), whose sum is σ = 1078992000. Its totient is φ = 133142016.

The previous prime is 388440623. The next prime is 388440673. The reversal of 388440640 is 46044883.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×388440640² = 301772261607219200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 388440640.

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, 107991 + ... + 111529.

Almost surely, 2^388440640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 388440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (539496000).

388440640 is an abundant number, since it is smaller than the sum of its proper divisors (690551360).

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

388440640 is an equidigital number, since it uses as much as digits as its factorization.

388440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3577 (or 3553 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 37.

The square root of 388440640 is about 19708.8974831166. The cubic root of 388440640 is about 729.6393038871.

The spelling of 388440640 in words is "three hundred eighty-eight million, four hundred forty thousand, six hundred forty".