1813664 has 36 divisors (see below), whose sum is σ = 3792474. Its totient is φ = 853632.

The previous prime is 1813639. The next prime is 1813667. The reversal of 1813664 is 4663181.

It can be written as a sum of positive squares in only one way, i.e., 1669264 + 144400 = 1292^2 + 380^2 .

It is not an unprimeable number, because it can be changed into a prime (1813667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11474 + ... + 11630.

2^1813664 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 1813664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896237).

1813664 is an abundant number, since it is smaller than the sum of its proper divisors (1978810).

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

1813664 is a wasteful number, since it uses less digits than its factorization.

1813664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 178 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 1813664 is about 1346.7234311469. The cubic root of 1813664 is about 121.9510687946.

The spelling of 1813664 in words is "one million, eight hundred thirteen thousand, six hundred sixty-four".