388009440 has 720 divisors, whose sum is σ = 1751948352. Its totient is φ = 80123904.

The previous prime is 388009421. The next prime is 388009451. The reversal of 388009440 is 44900883.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×388009440² = 301102651058227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 388009395 and 388009404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 8255497 + ... + 8255543.

Almost surely, 2^388009440 is an apocalyptic number.

388009440 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 388009440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (875974176).

388009440 is an abundant number, since it is smaller than the sum of its proper divisors (1363938912).

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

388009440 is a wasteful number, since it uses less digits than its factorization.

388009440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 388009440 is about 19697.9552238297. The cubic root of 388009440 is about 729.3692180402.

The spelling of 388009440 in words is "three hundred eighty-eight million, nine thousand, four hundred forty".