1091664 has 120 divisors (see below), whose sum is σ = 3779520. Its totient is φ = 295488.

The previous prime is 1091663. The next prime is 1091681. The reversal of 1091664 is 4661901.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57447 + ... + 57465.

It is an arithmetic number, because the mean of its divisors is an integer number (31496).

2^1091664 is an apocalyptic number.

1091664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1091664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1889760).

1091664 is an abundant number, since it is smaller than the sum of its proper divisors (2687856).

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

1091664 is a wasteful number, since it uses less digits than its factorization.

1091664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62 (or 31 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1091664 is about 1044.8272584499. The cubic root of 1091664 is about 102.9665898489.

The spelling of 1091664 in words is "one million, ninety-one thousand, six hundred sixty-four".