1639641 has 4 divisors (see below), whose sum is σ = 2186192. Its totient is φ = 1093092.

The previous prime is 1639613. The next prime is 1639663. The reversal of 1639641 is 1469361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1639641 - 2⁵ = 1639609 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1639599 and 1639608.

It is not an unprimeable number, because it can be changed into a prime (1639241) 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, 273271 + ... + 273276.

It is an arithmetic number, because the mean of its divisors is an integer number (546548).

2^1639641 is an apocalyptic number.

It is an amenable number.

1639641 is a deficient number, since it is larger than the sum of its proper divisors (546551).

1639641 is an equidigital number, since it uses as much as digits as its factorization.

1639641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546550.

The product of its digits is 3888, while the sum is 30.

The square root of 1639641 is about 1280.4846738638. The cubic root of 1639641 is about 117.9187653084.

The spelling of 1639641 in words is "one million, six hundred thirty-nine thousand, six hundred forty-one".