400003840 has 144 divisors (see below), whose sum is σ = 1003685760. Its totient is φ = 152616960.

The previous prime is 400003837. The next prime is 400003861. The reversal of 400003840 is 48300004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3669706 + ... + 3669814.

It is an arithmetic number, because the mean of its divisors is an integer number (6970040).

Almost surely, 2^400003840 is an apocalyptic number.

400003840 is a gapful number since it is divisible by the number (40) 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 400003840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (501842880).

400003840 is an abundant number, since it is smaller than the sum of its proper divisors (603681920).

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

400003840 is a wasteful number, since it uses less digits than its factorization.

400003840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 400003840 is about 20000.0959997696. The cubic root of 400003840 is about 736.8086575007.

Adding to 400003840 its reverse (48300004), we get a palindrome (448303844).

The spelling of 400003840 in words is "four hundred million, three thousand, eight hundred forty".