400242440 has 64 divisors (see below), whose sum is σ = 982195200. Its totient is φ = 145896192.

The previous prime is 400242439. The next prime is 400242443. The reversal of 400242440 is 44242004.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (400242443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36209 + ... + 45951.

It is an arithmetic number, because the mean of its divisors is an integer number (15346800).

Almost surely, 2^400242440 is an apocalyptic number.

400242440 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 400242440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (491097600).

400242440 is an abundant number, since it is smaller than the sum of its proper divisors (581952760).

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

400242440 is a wasteful number, since it uses less digits than its factorization.

400242440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9846 (or 9842 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

The square root of 400242440 is about 20006.0600818852. The cubic root of 400242440 is about 736.9551290964.

Adding to 400242440 its reverse (44242004), we get a palindrome (444484444).

The spelling of 400242440 in words is "four hundred million, two hundred forty-two thousand, four hundred forty".