1981138412 has 24 divisors (see below), whose sum is σ = 3806276880. Its totient is φ = 894778560.

The previous prime is 1981138363. The next prime is 1981138427. The reversal of 1981138412 is 2148311891.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136487 + ... + 150302.

It is an arithmetic number, because the mean of its divisors is an integer number (158594870).

Almost surely, 2^1981138412 is an apocalyptic number.

It is an amenable number.

1981138412 is a deficient number, since it is larger than the sum of its proper divisors (1825138468).

1981138412 is a wasteful number, since it uses less digits than its factorization.

1981138412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286961 (or 286959 counting only the distinct ones).

The product of its digits is 13824, while the sum is 38.

The square root of 1981138412 is about 44509.9810379650. The cubic root of 1981138412 is about 1255.9478481530.

The spelling of 1981138412 in words is "one billion, nine hundred eighty-one million, one hundred thirty-eight thousand, four hundred twelve".