4006440 has 96 divisors (see below), whose sum is σ = 13478400. Its totient is φ = 1031040.

The previous prime is 4006423. The next prime is 4006451. The reversal of 4006440 is 446004.

It is a super-2 number, since 2×4006440² = 32103122947200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10981 + ... + 11339.

It is an arithmetic number, because the mean of its divisors is an integer number (140400).

Almost surely, 2^4006440 is an apocalyptic number.

4006440 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 4006440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6739200).

4006440 is an abundant number, since it is smaller than the sum of its proper divisors (9471960).

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

4006440 is a wasteful number, since it uses less digits than its factorization.

4006440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 4006440 is about 2001.6093524961. The cubic root of 4006440 is about 158.8252500419.

It can be divided in two parts, 40064 and 40, that added together give a palindrome (40104).

The spelling of 4006440 in words is "four million, six thousand, four hundred forty".