400004390 has 32 divisors (see below), whose sum is σ = 771573600. Its totient is φ = 148770304.

The previous prime is 400004351. The next prime is 400004399. The reversal of 400004390 is 93400004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400004399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65 + ... + 28284.

It is an arithmetic number, because the mean of its divisors is an integer number (24111675).

Almost surely, 2^400004390 is an apocalyptic number.

400004390 is a deficient number, since it is larger than the sum of its proper divisors (371569210).

400004390 is a wasteful number, since it uses less digits than its factorization.

400004390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28456.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 400004390 is about 20000.1097496989. The cubic root of 400004390 is about 736.8089952013.

Adding to 400004390 its reverse (93400004), we get a palindrome (493404394).

The spelling of 400004390 in words is "four hundred million, four thousand, three hundred ninety".