400445 has 6 divisors (see below), whose sum is σ = 482238. Its totient is φ = 319224.

The previous prime is 400441. The next prime is 400457. The reversal of 400445 is 544004.

It can be written as a sum of positive squares in only one way, i.e., 320356 + 80089 = 566^2 + 283^2 .

It is not a de Polignac number, because 400445 - 2² = 400441 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1274 + ... + 1556.

It is an arithmetic number, because the mean of its divisors is an integer number (80373).

2⁴⁰⁰⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

400445 is a deficient number, since it is larger than the sum of its proper divisors (81793).

400445 is an frugal number, since it uses more digits than its factorization.

400445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 17.

The square root of 400445 is about 632.8072376324. The cubic root of 400445 is about 73.7079430803.

Multiplying 400445 by its product of nonzero digits (320), we get a square (128142400 = 11320²).

Adding to 400445 its reverse (544004), we get a palindrome (944449).

The spelling of 400445 in words is "four hundred thousand, four hundred forty-five".