1081555668 has 72 divisors (see below), whose sum is σ = 2790365760. Its totient is φ = 353122560.

The previous prime is 1081555633. The next prime is 1081555729. The reversal of 1081555668 is 8665551801.

1081555668 is a `hidden beast` number, since 1 + 0 + 81 + 5 + 5 + 566 + 8 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 715033 + ... + 716543.

It is an arithmetic number, because the mean of its divisors is an integer number (38755080).

Almost surely, 2^1081555668 is an apocalyptic number.

1081555668 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 1081555668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1395182880).

1081555668 is an abundant number, since it is smaller than the sum of its proper divisors (1708810092).

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

1081555668 is a wasteful number, since it uses less digits than its factorization.

1081555668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1917 (or 1912 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 45.

The square root of 1081555668 is about 32887.0136680119. The cubic root of 1081555668 is about 1026.4779529363.

The spelling of 1081555668 in words is "one billion, eighty-one million, five hundred fifty-five thousand, six hundred sixty-eight".