1188121788 has 72 divisors (see below), whose sum is σ = 3452318688. Its totient is φ = 337488768.

The previous prime is 1188121783. The next prime is 1188121801. The reversal of 1188121788 is 8871218811.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1188121783) 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, 29970 + ... + 57222.

Almost surely, 2^1188121788 is an apocalyptic number.

1188121788 is a gapful number since it is divisible by the number (18) 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 1188121788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1726159344).

1188121788 is an abundant number, since it is smaller than the sum of its proper divisors (2264196900).

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

1188121788 is a wasteful number, since it uses less digits than its factorization.

1188121788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27443 (or 27438 counting only the distinct ones).

The product of its digits is 57344, while the sum is 45.

The square root of 1188121788 is about 34469.1425480820. The cubic root of 1188121788 is about 1059.1406907806.

The spelling of 1188121788 in words is "one billion, one hundred eighty-eight million, one hundred twenty-one thousand, seven hundred eighty-eight".