1643425 has 12 divisors (see below), whose sum is σ = 2329216. Its totient is φ = 1126800.

The previous prime is 1643423. The next prime is 1643431. The reversal of 1643425 is 5243461.

It is not a de Polignac number, because 1643425 - 2¹ = 1643423 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a d-powerful number, because it can be written as 1 + 6⁶ + 4² + 3¹³ + 4⁴ + 2¹¹ + 5³ .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1643425.

It is not an unprimeable number, because it can be changed into a prime (1643423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4521 + ... + 4870.

2^1643425 is an apocalyptic number.

It is an amenable number.

1643425 is a deficient number, since it is larger than the sum of its proper divisors (685791).

1643425 is an equidigital number, since it uses as much as digits as its factorization.

1643425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9408 (or 9403 counting only the distinct ones).

The product of its digits is 2880, while the sum is 25.

The square root of 1643425 is about 1281.9613878741. The cubic root of 1643425 is about 118.0094074660.

Adding to 1643425 its reverse (5243461), we get a palindrome (6886886).

The spelling of 1643425 in words is "one million, six hundred forty-three thousand, four hundred twenty-five".