1992981991 has 32 divisors (see below), whose sum is σ = 2816755200. Its totient is φ = 1358052480.

The previous prime is 1992981923. The next prime is 1992982003. The reversal of 1992981991 is 1991892991.

It is a cyclic number.

It is not a de Polignac number, because 1992981991 - 2¹⁹ = 1992457703 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1992981391) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33376 + ... + 71413.

It is an arithmetic number, because the mean of its divisors is an integer number (88023600).

Almost surely, 2^1992981991 is an apocalyptic number.

1992981991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1992981991 is a deficient number, since it is larger than the sum of its proper divisors (823773209).

1992981991 is a wasteful number, since it uses less digits than its factorization.

1992981991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104839.

The product of its digits is 944784, while the sum is 58.

The square root of 1992981991 is about 44642.8268706183. The cubic root of 1992981991 is about 1258.4456332544.

The spelling of 1992981991 in words is "one billion, nine hundred ninety-two million, nine hundred eighty-one thousand, nine hundred ninety-one".