1181661568 has 64 divisors (see below), whose sum is σ = 2500264800. Its totient is φ = 554360832.

The previous prime is 1181661511. The next prime is 1181661571. The reversal of 1181661568 is 8651661811.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×1181661568² = 2792648122576437248, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 954646 + ... + 955882.

Almost surely, 2^1181661568 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 1181661568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1250132400).

1181661568 is an abundant number, since it is smaller than the sum of its proper divisors (1318603232).

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

1181661568 is a wasteful number, since it uses less digits than its factorization.

1181661568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1707 (or 1695 counting only the distinct ones).

The product of its digits is 69120, while the sum is 43.

The square root of 1181661568 is about 34375.3046241048. The cubic root of 1181661568 is about 1057.2175656131.

The spelling of 1181661568 in words is "one billion, one hundred eighty-one million, six hundred sixty-one thousand, five hundred sixty-eight".