20191284 has 18 divisors (see below), whose sum is σ = 51039170. Its totient is φ = 6730416.

The previous prime is 20191277. The next prime is 20191333. The reversal of 20191284 is 48219102.

It can be written as a sum of positive squares in only one way, i.e., 11370384 + 8820900 = 3372^2 + 2970^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 280399 + ... + 280470.

Almost surely, 2^20191284 is an apocalyptic number.

It is an amenable number.

20191284 is an abundant number, since it is smaller than the sum of its proper divisors (30847886).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20191284 is a wasteful number, since it uses less digits than its factorization.

20191284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560879 (or 560874 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 20191284 is about 4493.4712639562. The cubic root of 20191284 is about 272.3043917867.

The spelling of 20191284 in words is "twenty million, one hundred ninety-one thousand, two hundred eighty-four".