400000189 has 2 divisors, whose sum is σ = 400000190. Its totient is φ = 400000188.

The previous prime is 400000171. The next prime is 400000193. The reversal of 400000189 is 981000004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 396607225 + 3392964 = 19915^2 + 1842^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400000189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400000109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200000094 + 200000095.

It is an arithmetic number, because the mean of its divisors is an integer number (200000095).

Almost surely, 2^400000189 is an apocalyptic number.

It is an amenable number.

400000189 is a deficient number, since it is larger than the sum of its proper divisors (1).

400000189 is an equidigital number, since it uses as much as digits as its factorization.

400000189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 400000189 is about 20000.0047249994. The cubic root of 400000189 is about 736.8064157751.

The spelling of 400000189 in words is "four hundred million, one hundred eighty-nine", and thus it is an aban number.