1664660 has 12 divisors (see below), whose sum is σ = 3495828. Its totient is φ = 665856.

The previous prime is 1664653. The next prime is 1664681. The reversal of 1664660 is 664661.

It can be written as a sum of positive squares in 2 ways, for example, as 1249924 + 414736 = 1118^2 + 644^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41597 + ... + 41636.

It is an arithmetic number, because the mean of its divisors is an integer number (291319).

2^1664660 is an apocalyptic number.

1664660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664660 is an abundant number, since it is smaller than the sum of its proper divisors (1831168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1664660 is a wasteful number, since it uses less digits than its factorization.

1664660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83242 (or 83240 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 1664660 is about 1290.2170360060. The cubic root of 1664660 is about 118.5155077119.

Subtracting from 1664660 its reverse (664661), we obtain a palindrome (999999).

The spelling of 1664660 in words is "one million, six hundred sixty-four thousand, six hundred sixty".