1981142568 has 48 divisors (see below), whose sum is σ = 5379678720. Its totient is φ = 658647456.

The previous prime is 1981142507. The next prime is 1981142621. The reversal of 1981142568 is 8652411891.

It is a happy number.

1981142568 is a `hidden beast` number, since 1 + 9 + 81 + 1 + 4 + 2 + 568 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8346 + ... + 63497.

It is an arithmetic number, because the mean of its divisors is an integer number (112076640).

Almost surely, 2^1981142568 is an apocalyptic number.

1981142568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1981142568 is an abundant number, since it is smaller than the sum of its proper divisors (3398536152).

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

1981142568 is a wasteful number, since it uses less digits than its factorization.

1981142568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72238 (or 72231 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 1981142568 is about 44510.0277240983. The cubic root of 1981142568 is about 1255.9487263881.

The spelling of 1981142568 in words is "one billion, nine hundred eighty-one million, one hundred forty-two thousand, five hundred sixty-eight".