1664628 has 72 divisors (see below), whose sum is σ = 4788000. Its totient is φ = 447552.

The previous prime is 1664627. The next prime is 1664633. The reversal of 1664628 is 8264661.

It is a happy number.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11098 + ... + 11246.

It is an arithmetic number, because the mean of its divisors is an integer number (66500).

2^1664628 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 1664628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2394000).

1664628 is an abundant number, since it is smaller than the sum of its proper divisors (3123372).

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

1664628 is a wasteful number, since it uses less digits than its factorization.

1664628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 180 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 1664628 is about 1290.2046349320. The cubic root of 1664628 is about 118.5147482935.

Adding to 1664628 its sum of digits (33), we get a palindrome (1664661).

The spelling of 1664628 in words is "one million, six hundred sixty-four thousand, six hundred twenty-eight".