1138531968 has 192 divisors, whose sum is σ = 3809332800. Its totient is φ = 319647744.

The previous prime is 1138531937. The next prime is 1138531969. The reversal of 1138531968 is 8691358311.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (1138531969) 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, 474580 + ... + 476972.

It is an arithmetic number, because the mean of its divisors is an integer number (19840275).

Almost surely, 2^1138531968 is an apocalyptic number.

1138531968 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 1138531968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1904666400).

1138531968 is an abundant number, since it is smaller than the sum of its proper divisors (2670800832).

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

1138531968 is a wasteful number, since it uses less digits than its factorization.

1138531968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2479 (or 2464 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 1138531968 is about 33742.1393512622. The cubic root of 1138531968 is about 1044.1953217146.

The spelling of 1138531968 in words is "one billion, one hundred thirty-eight million, five hundred thirty-one thousand, nine hundred sixty-eight".