1643225 has 6 divisors (see below), whose sum is σ = 2037630. Its totient is φ = 1314560.

The previous prime is 1643221. The next prime is 1643231. The reversal of 1643225 is 5223461.

1643225 = T₃₅₀ + T₃₅₁ + ... + T₃₇₄.

It can be written as a sum of positive squares in 3 ways, for example, as 234256 + 1408969 = 484^2 + 1187^2 .

It is not a de Polignac number, because 1643225 - 2² = 1643221 is a prime.

It is a d-powerful number, because it can be written as 1 + 6⁶ + 4³ + 3¹³ + 2⁷ + 2¹¹ + 5 .

It is a self number, because there is not a number n which added to its sum of digits gives 1643225.

It is not an unprimeable number, because it can be changed into a prime (1643221) 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, 32840 + ... + 32889.

It is an arithmetic number, because the mean of its divisors is an integer number (339605).

2^1643225 is an apocalyptic number.

It is an amenable number.

1643225 is a deficient number, since it is larger than the sum of its proper divisors (394405).

1643225 is an equidigital number, since it uses as much as digits as its factorization.

1643225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65739 (or 65734 counting only the distinct ones).

The product of its digits is 1440, while the sum is 23.

The square root of 1643225 is about 1281.8833800311. The cubic root of 1643225 is about 118.0046201389.

Adding to 1643225 its reverse (5223461), we get a palindrome (6866686).

The spelling of 1643225 in words is "one million, six hundred forty-three thousand, two hundred twenty-five".