19821049 has 2 divisors, whose sum is σ = 19821050. Its totient is φ = 19821048.

The previous prime is 19821041. The next prime is 19821071. The reversal of 19821049 is 94012891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15155449 + 4665600 = 3893^2 + 2160^2 .

It is a cyclic number.

It is not a de Polignac number, because 19821049 - 2³ = 19821041 is a prime.

It is not a weakly prime, because it can be changed into another prime (19821041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9910524 + 9910525.

It is an arithmetic number, because the mean of its divisors is an integer number (9910525).

Almost surely, 2^19821049 is an apocalyptic number.

It is an amenable number.

19821049 is a deficient number, since it is larger than the sum of its proper divisors (1).

19821049 is an equidigital number, since it uses as much as digits as its factorization.

19821049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 19821049 is about 4452.0836694743. The cubic root of 19821049 is about 270.6297554221.

The spelling of 19821049 in words is "nineteen million, eight hundred twenty-one thousand, forty-nine".