20285989 has 2 divisors, whose sum is σ = 20285990. Its totient is φ = 20285988.

The previous prime is 20285983. The next prime is 20286017. The reversal of 20285989 is 98958202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12723489 + 7562500 = 3567^2 + 2750^2 .

It is a cyclic number.

It is not a de Polignac number, because 20285989 - 2⁹ = 20285477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20285983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10142994 + 10142995.

It is an arithmetic number, because the mean of its divisors is an integer number (10142995).

Almost surely, 2^20285989 is an apocalyptic number.

It is an amenable number.

20285989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20285989 is an equidigital number, since it uses as much as digits as its factorization.

20285989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 20285989 is about 4503.9970026633. The cubic root of 20285989 is about 272.7294658376.

The spelling of 20285989 in words is "twenty million, two hundred eighty-five thousand, nine hundred eighty-nine".