19881081 has 24 divisors (see below), whose sum is σ = 31468320. Its totient is φ = 11995200.

The previous prime is 19881079. The next prime is 19881097. The reversal of 19881081 is 18018891.

It is not a de Polignac number, because 19881081 - 2¹ = 19881079 is a prime.

It is a super-2 number, since 2×19881081² = 790514763457122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19881481) 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, 40246 + ... + 40736.

It is an arithmetic number, because the mean of its divisors is an integer number (1311180).

Almost surely, 2^19881081 is an apocalyptic number.

19881081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19881081 is a deficient number, since it is larger than the sum of its proper divisors (11587239).

19881081 is a wasteful number, since it uses less digits than its factorization.

19881081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917 (or 914 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 19881081 is about 4458.8205839661. The cubic root of 19881081 is about 270.9026987823.

It can be divided in two parts, 198810 and 81, that added together give a palindrome (198891).

The spelling of 19881081 in words is "nineteen million, eight hundred eighty-one thousand, eighty-one".