400189 has 4 divisors (see below), whose sum is σ = 402400. Its totient is φ = 397980.

The previous prime is 400187. The next prime is 400199. The reversal of 400189 is 981004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 400189 - 2¹ = 400187 is a prime.

It is a Duffinian number.

400189 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807 + ... + 1204.

It is an arithmetic number, because the mean of its divisors is an integer number (100600).

2⁴⁰⁰¹⁸⁹ is an apocalyptic number.

It is an amenable number.

400189 is a deficient number, since it is larger than the sum of its proper divisors (2211).

400189 is a wasteful number, since it uses less digits than its factorization.

400189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2210.

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

The square root of 400189 is about 632.6049320073. The cubic root of 400189 is about 73.6922328448.

The spelling of 400189 in words is "four hundred thousand, one hundred eighty-nine".