209899117 has 2 divisors, whose sum is σ = 209899118. Its totient is φ = 209899116.

The previous prime is 209899103. The next prime is 209899199. The reversal of 209899117 is 711998902.

It is a happy number.

209899117 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208686916 + 1212201 = 14446^2 + 1101^2 .

It is a cyclic number.

It is not a de Polignac number, because 209899117 - 2¹¹ = 209897069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209899717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104949558 + 104949559.

It is an arithmetic number, because the mean of its divisors is an integer number (104949559).

Almost surely, 2^209899117 is an apocalyptic number.

It is an amenable number.

209899117 is a deficient number, since it is larger than the sum of its proper divisors (1).

209899117 is an equidigital number, since it uses as much as digits as its factorization.

209899117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 46.

The square root of 209899117 is about 14487.8955338586. The cubic root of 209899117 is about 594.2969989707.

The spelling of 209899117 in words is "two hundred nine million, eight hundred ninety-nine thousand, one hundred seventeen".