209933862767989 has 2 divisors, whose sum is σ = 209933862767990. Its totient is φ = 209933862767988.

The previous prime is 209933862767987. The next prime is 209933862768067. The reversal of 209933862767989 is 989767268339902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 175436647562500 + 34497215205489 = 13245250^2 + 5873433^2 .

It is a cyclic number.

It is not a de Polignac number, because 209933862767989 - 2¹ = 209933862767987 is a prime.

Together with 209933862767987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209933862767987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104966931383994 + 104966931383995.

It is an arithmetic number, because the mean of its divisors is an integer number (104966931383995).

Almost surely, 2^{209933862767989} is an apocalyptic number.

It is an amenable number.

209933862767989 is a deficient number, since it is larger than the sum of its proper divisors (1).

209933862767989 is an equidigital number, since it uses as much as digits as its factorization.

209933862767989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26665583616, while the sum is 88.

The spelling of 209933862767989 in words is "two hundred nine trillion, nine hundred thirty-three billion, eight hundred sixty-two million, seven hundred sixty-seven thousand, nine hundred eighty-nine".