1181664 has 72 divisors (see below), whose sum is σ = 3675672. Its totient is φ = 357120.

The previous prime is 1181647. The next prime is 1181681. The reversal of 1181664 is 4661811.

It is an interprime number because it is at equal distance from previous prime (1181647) and next prime (1181681).

It is a tau number, because it is divible by the number of its divisors (72).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2982 + ... + 3354.

It is an arithmetic number, because the mean of its divisors is an integer number (51051).

2^1181664 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 1181664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1837836).

1181664 is an abundant number, since it is smaller than the sum of its proper divisors (2494008).

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

1181664 is a wasteful number, since it uses less digits than its factorization.

1181664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400 (or 389 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 1181664 is about 1087.0436973738. The cubic root of 1181664 is about 105.7218290906.

The spelling of 1181664 in words is "one million, one hundred eighty-one thousand, six hundred sixty-four".