1664839 has 6 divisors (see below), whose sum is σ = 1830080. Its totient is φ = 1513380.

The previous prime is 1664833. The next prime is 1664849. The reversal of 1664839 is 9384661.

It is not a de Polignac number, because 1664839 - 2⁵ = 1664807 is a prime.

It is a Duffinian number.

1664839 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1664798 and 1664807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664833) 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, 6759 + ... + 7000.

2^1664839 is an apocalyptic number.

1664839 is a deficient number, since it is larger than the sum of its proper divisors (165241).

1664839 is a wasteful number, since it uses less digits than its factorization.

1664839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13781 (or 13770 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 1664839 is about 1290.2864023154. The cubic root of 1664839 is about 118.5197555294.

It can be divided in two parts, 166 and 4839, that added together give a palindrome (5005).

The spelling of 1664839 in words is "one million, six hundred sixty-four thousand, eight hundred thirty-nine".