1664624 has 40 divisors (see below), whose sum is σ = 3562272. Its totient is φ = 748800.

The previous prime is 1664569. The next prime is 1664627. The reversal of 1664624 is 4264661.

It is a super-2 number, since 2×1664624² = 5541946122752, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664627) 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, 10949 + ... + 11099.

2^1664624 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1664624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1781136).

1664624 is an abundant number, since it is smaller than the sum of its proper divisors (1897648).

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

1664624 is a wasteful number, since it uses less digits than its factorization.

1664624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 219 counting only the distinct ones).

The product of its digits is 6912, while the sum is 29.

The square root of 1664624 is about 1290.2030847894. The cubic root of 1664624 is about 118.5146533655.

The spelling of 1664624 in words is "one million, six hundred sixty-four thousand, six hundred twenty-four".