19881284 has 12 divisors (see below), whose sum is σ = 35732844. Its totient is φ = 9671904.

The previous prime is 19881283. The next prime is 19881311. The reversal of 19881284 is 48218891.

19881284 = 367² + 368² + ... + 477².

It can be written as a sum of positive squares in 2 ways, for example, as 15429184 + 4452100 = 3928^2 + 2110^2 .

It is not an unprimeable number, because it can be changed into a prime (19881283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67019 + ... + 67314.

It is an arithmetic number, because the mean of its divisors is an integer number (2977737).

Almost surely, 2^19881284 is an apocalyptic number.

It is an amenable number.

19881284 is a deficient number, since it is larger than the sum of its proper divisors (15851560).

19881284 is a wasteful number, since it uses less digits than its factorization.

19881284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134374 (or 134372 counting only the distinct ones).

The product of its digits is 36864, while the sum is 41.

The square root of 19881284 is about 4458.8433477753. The cubic root of 19881284 is about 270.9036208157.

The spelling of 19881284 in words is "nineteen million, eight hundred eighty-one thousand, two hundred eighty-four".