400039805 has 32 divisors (see below), whose sum is σ = 553512960. Its totient is φ = 274697280.

The previous prime is 400039789. The next prime is 400039807. The reversal of 400039805 is 508930004.

It is not a de Polignac number, because 400039805 - 2⁴ = 400039789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400039807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97934 + ... + 101936.

It is an arithmetic number, because the mean of its divisors is an integer number (17297280).

Almost surely, 2^400039805 is an apocalyptic number.

It is an amenable number.

400039805 is a deficient number, since it is larger than the sum of its proper divisors (153473155).

400039805 is a wasteful number, since it uses less digits than its factorization.

400039805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4121.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 400039805 is about 20000.9951002444. The cubic root of 400039805 is about 736.8307393964.

Adding to 400039805 its reverse (508930004), we get a palindrome (908969809).

The spelling of 400039805 in words is "four hundred million, thirty-nine thousand, eight hundred five".