400240044 has 144 divisors (see below), whose sum is σ = 1117404288. Its totient is φ = 120282624.

The previous prime is 400240033. The next prime is 400240081. The reversal of 400240044 is 440042004.

It is a happy number.

It is a super-2 number, since 2×400240044² = 320384185642243872, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 400239999 and 400240026.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1763059 + ... + 1763285.

It is an arithmetic number, because the mean of its divisors is an integer number (7759752).

Almost surely, 2^400240044 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 400240044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (558702144).

400240044 is an abundant number, since it is smaller than the sum of its proper divisors (717164244).

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

400240044 is a wasteful number, since it uses less digits than its factorization.

400240044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

The square root of 400240044 is about 20006.0001999400. Note that the first 3 decimals coincide. The cubic root of 400240044 is about 736.9536585310.

Adding to 400240044 its reverse (440042004), we get a palindrome (840282048).

The spelling of 400240044 in words is "four hundred million, two hundred forty thousand, forty-four".