19881087 has 16 divisors (see below), whose sum is σ = 28224000. Its totient is φ = 12412224.

The previous prime is 19881079. The next prime is 19881097. The reversal of 19881087 is 78018891.

It is not a de Polignac number, because 19881087 - 2³ = 19881079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19881077) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3114 + ... + 7032.

It is an arithmetic number, because the mean of its divisors is an integer number (1764000).

Almost surely, 2^19881087 is an apocalyptic number.

19881087 is a deficient number, since it is larger than the sum of its proper divisors (8342913).

19881087 is a wasteful number, since it uses less digits than its factorization.

19881087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4030.

The product of its (nonzero) digits is 32256, while the sum is 42.

The square root of 19881087 is about 4458.8212567897. The cubic root of 19881087 is about 270.9027260346.

The spelling of 19881087 in words is "nineteen million, eight hundred eighty-one thousand, eighty-seven".