400644409 has 8 divisors (see below), whose sum is σ = 443223360. Its totient is φ = 359091600.

The previous prime is 400644379. The next prime is 400644451. The reversal of 400644409 is 904446004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400644409 - 2⁷ = 400644281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400644499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255714 + ... + 257275.

It is an arithmetic number, because the mean of its divisors is an integer number (55402920).

Almost surely, 2^400644409 is an apocalyptic number.

It is an amenable number.

400644409 is a deficient number, since it is larger than the sum of its proper divisors (42578951).

400644409 is a wasteful number, since it uses less digits than its factorization.

400644409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513071.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 400644409 is about 20016.1037417376. The cubic root of 400644409 is about 737.2017579490.

It can be divided in two parts, 400 and 644409, that added together give a square (644809 = 803²).

The spelling of 400644409 in words is "four hundred million, six hundred forty-four thousand, four hundred nine".