1664216 has 16 divisors (see below), whose sum is σ = 3135840. Its totient is φ = 828000.

The previous prime is 1664123. The next prime is 1664227. The reversal of 1664216 is 6124661.

It is a happy number.

It is a super-2 number, since 2×1664216² = 5539229789312, which contains 22 as substring.

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, 1841 + ... + 2591.

It is an arithmetic number, because the mean of its divisors is an integer number (195990).

2^1664216 is an apocalyptic number.

It is an amenable number.

1664216 is a deficient number, since it is larger than the sum of its proper divisors (1471624).

1664216 is a wasteful number, since it uses less digits than its factorization.

1664216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034 (or 1030 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 1664216 is about 1290.0449604568. The cubic root of 1664216 is about 118.5049699115.

Adding to 1664216 its reverse (6124661), we get a palindrome (7788877).

The spelling of 1664216 in words is "one million, six hundred sixty-four thousand, two hundred sixteen".