400221889 has 2 divisors, whose sum is σ = 400221890. Its totient is φ = 400221888.

The previous prime is 400221751. The next prime is 400221911. The reversal of 400221889 is 988122004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 296528400 + 103693489 = 17220^2 + 10183^2 .

It is a cyclic number.

It is not a de Polignac number, because 400221889 - 2²¹ = 398124737 is a prime.

It is not a weakly prime, because it can be changed into another prime (400251889) 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, 200110944 + 200110945.

It is an arithmetic number, because the mean of its divisors is an integer number (200110945).

Almost surely, 2^400221889 is an apocalyptic number.

It is an amenable number.

400221889 is a deficient number, since it is larger than the sum of its proper divisors (1).

400221889 is an equidigital number, since it uses as much as digits as its factorization.

400221889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 400221889 is about 20005.5464559207. The cubic root of 400221889 is about 736.9425155547.

The spelling of 400221889 in words is "four hundred million, two hundred twenty-one thousand, eight hundred eighty-nine".