400289 has 4 divisors (see below), whose sum is σ = 401556. Its totient is φ = 399024.

The previous prime is 400277. The next prime is 400291. The reversal of 400289 is 982004.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 30625 + 369664 = 175^2 + 608^2 .

It is a cyclic number.

It is not a de Polignac number, because 400289 - 2⁸ = 400033 is a prime.

It is a d-powerful number, because it can be written as 4⁹ + 0 + 2¹⁷ + 0 + 8³ + 9⁴ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287 + ... + 939.

It is an arithmetic number, because the mean of its divisors is an integer number (100389).

2⁴⁰⁰²⁸⁹ is an apocalyptic number.

It is an amenable number.

400289 is a deficient number, since it is larger than the sum of its proper divisors (1267).

400289 is an equidigital number, since it uses as much as digits as its factorization.

400289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 400289 is about 632.6839653413. The cubic root of 400289 is about 73.6983704527.

It can be divided in two parts, 400 and 289, that multiplied together give a square (115600 = 340²).

The spelling of 400289 in words is "four hundred thousand, two hundred eighty-nine".