400640244 has 12 divisors (see below), whose sum is σ = 934827264. Its totient is φ = 133546744.

The previous prime is 400640237. The next prime is 400640281. The reversal of 400640244 is 442046004.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×400640244² = 321025210224759072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16693332 + ... + 16693355.

It is an arithmetic number, because the mean of its divisors is an integer number (77902272).

Almost surely, 2^400640244 is an apocalyptic number.

It is an amenable number.

400640244 is an abundant number, since it is smaller than the sum of its proper divisors (534187020).

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

400640244 is a wasteful number, since it uses less digits than its factorization.

400640244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33386694 (or 33386692 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 400640244 is about 20015.9997002398. Note that the first 3 decimals coincide. The cubic root of 400640244 is about 737.1992033512.

Adding to 400640244 its reverse (442046004), we get a palindrome (842686248).

The spelling of 400640244 in words is "four hundred million, six hundred forty thousand, two hundred forty-four".