1001664 has 84 divisors (see below), whose sum is σ = 3011424. Its totient is φ = 317952.

The previous prime is 1001659. The next prime is 1001669. The reversal of 1001664 is 4661001.

1001664 is a `hidden beast` number, since 1 + 0 + 0 + 1 + 664 = 666.

It is an interprime number because it is at equal distance from previous prime (1001659) and next prime (1001669).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1001669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21289 + ... + 21335.

2^1001664 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 1001664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1505712).

1001664 is an abundant number, since it is smaller than the sum of its proper divisors (2009760).

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

1001664 is a wasteful number, since it uses less digits than its factorization.

1001664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1001664 is about 1000.8316541757. The cubic root of 1001664 is about 100.0554359296.

Adding to 1001664 its reverse (4661001), we get a palindrome (5662665).

It can be divided in two parts, 100 and 1664, that added together give a square (1764 = 42²).

The spelling of 1001664 in words is "one million, one thousand, six hundred sixty-four".