1115911638 has 48 divisors (see below), whose sum is σ = 2487270240. Its totient is φ = 361317888.

The previous prime is 1115911633. The next prime is 1115911649. The reversal of 1115911638 is 8361195111.

1115911638 is a `hidden beast` number, since 1 + 1 + 1 + 5 + 9 + 11 + 638 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1115911633) 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, 589798 + ... + 591686.

It is an arithmetic number, because the mean of its divisors is an integer number (51818130).

Almost surely, 2^1115911638 is an apocalyptic number.

1115911638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1115911638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1243635120).

1115911638 is an abundant number, since it is smaller than the sum of its proper divisors (1371358602).

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

1115911638 is a wasteful number, since it uses less digits than its factorization.

1115911638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2821 (or 2818 counting only the distinct ones).

The product of its digits is 6480, while the sum is 36.

The square root of 1115911638 is about 33405.2636271591. The cubic root of 1115911638 is about 1037.2336609216.

The spelling of 1115911638 in words is "one billion, one hundred fifteen million, nine hundred eleven thousand, six hundred thirty-eight".