400440091 has 8 divisors (see below), whose sum is σ = 416033280. Its totient is φ = 384965952.

The previous prime is 400440077. The next prime is 400440107. The reversal of 400440091 is 190044004.

It is a happy number.

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

It is not a de Polignac number, because 400440091 - 2¹⁵ = 400407323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400440041) 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 7 ways as a sum of consecutive naturals, for example, 22875 + ... + 36388.

It is an arithmetic number, because the mean of its divisors is an integer number (52004160).

Almost surely, 2^400440091 is an apocalyptic number.

400440091 is a deficient number, since it is larger than the sum of its proper divisors (15593189).

400440091 is a wasteful number, since it uses less digits than its factorization.

400440091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59525.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 400440091 is about 20010.9992504123. Note that the first 3 decimals coincide. The cubic root of 400440091 is about 737.0764188725.

Adding to 400440091 its reverse (190044004), we get a palindrome (590484095).

The spelling of 400440091 in words is "four hundred million, four hundred forty thousand, ninety-one".