400220191 has 12 divisors (see below), whose sum is σ = 466624800. Its totient is φ = 342263040.

The previous prime is 400220179. The next prime is 400220201. The reversal of 400220191 is 191022004.

It is not a de Polignac number, because 400220191 - 2⁹ = 400219679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400220111) 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 11 ways as a sum of consecutive naturals, for example, 12906 + ... + 31096.

It is an arithmetic number, because the mean of its divisors is an integer number (38885400).

Almost surely, 2^400220191 is an apocalyptic number.

400220191 is a deficient number, since it is larger than the sum of its proper divisors (66404609).

400220191 is a wasteful number, since it uses less digits than its factorization.

400220191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18654 (or 18647 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 400220191 is about 20005.5040176447. The cubic root of 400220191 is about 736.9414733577.

Adding to 400220191 its reverse (191022004), we get a palindrome (591242195).

The spelling of 400220191 in words is "four hundred million, two hundred twenty thousand, one hundred ninety-one".