1643401 has 8 divisors (see below), whose sum is σ = 1729800. Its totient is φ = 1559040.

The previous prime is 1643387. The next prime is 1643423. The reversal of 1643401 is 1043461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 78400 + 1565001 = 280^2 + 1251^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1643401 - 2⁷ = 1643273 is a prime.

It is a Duffinian number.

1643401 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1643431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1305 + ... + 2233.

It is an arithmetic number, because the mean of its divisors is an integer number (216225).

2^1643401 is an apocalyptic number.

It is an amenable number.

1643401 is a deficient number, since it is larger than the sum of its proper divisors (86399).

1643401 is an equidigital number, since it uses as much as digits as its factorization.

1643401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1643401 is about 1281.9520271835. The cubic root of 1643401 is about 118.0088330073.

Adding to 1643401 its reverse (1043461), we get a palindrome (2686862).

The spelling of 1643401 in words is "one million, six hundred forty-three thousand, four hundred one".