1181381436 has 144 divisors (see below), whose sum is σ = 3220753536. Its totient is φ = 378333504.

The previous prime is 1181381431. The next prime is 1181381437. The reversal of 1181381436 is 6341831811.

1181381436 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1181381436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181381431) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3847995 + ... + 3848301.

It is an arithmetic number, because the mean of its divisors is an integer number (22366344).

Almost surely, 2^1181381436 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 1181381436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1610376768).

1181381436 is an abundant number, since it is smaller than the sum of its proper divisors (2039372100).

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

1181381436 is a wasteful number, since it uses less digits than its factorization.

1181381436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 456 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1181381436 is about 34371.2297714237. The cubic root of 1181381436 is about 1057.1340154988.

The spelling of 1181381436 in words is "one billion, one hundred eighty-one million, three hundred eighty-one thousand, four hundred thirty-six".