400188869 has 2 divisors, whose sum is σ = 400188870. Its totient is φ = 400188868.

The previous prime is 400188863. The next prime is 400188907. The reversal of 400188869 is 968881004.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 258888100 + 141300769 = 16090^2 + 11887^2 .

It is a cyclic number.

It is not a de Polignac number, because 400188869 - 2¹² = 400184773 is a prime.

It is a super-2 number, since 2×400188869² = 320302261742998322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400188863) 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 as a sum of consecutive naturals, namely, 200094434 + 200094435.

It is an arithmetic number, because the mean of its divisors is an integer number (200094435).

Almost surely, 2^400188869 is an apocalyptic number.

It is an amenable number.

400188869 is a deficient number, since it is larger than the sum of its proper divisors (1).

400188869 is an equidigital number, since it uses as much as digits as its factorization.

400188869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 110592, while the sum is 44.

The square root of 400188869 is about 20004.7211677644. The cubic root of 400188869 is about 736.9222480383.

The spelling of 400188869 in words is "four hundred million, one hundred eighty-eight thousand, eight hundred sixty-nine".