209788149 has 4 divisors (see below), whose sum is σ = 279717536. Its totient is φ = 139858764.

The previous prime is 209788147. The next prime is 209788171. The reversal of 209788149 is 941887902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 209788149 - 2¹ = 209788147 is a prime.

It is a super-2 number, since 2×209788149² = 88022134921692402, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 209788098 and 209788107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209788147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34964689 + ... + 34964694.

It is an arithmetic number, because the mean of its divisors is an integer number (69929384).

Almost surely, 2^209788149 is an apocalyptic number.

It is an amenable number.

209788149 is a deficient number, since it is larger than the sum of its proper divisors (69929387).

209788149 is an equidigital number, since it uses as much as digits as its factorization.

209788149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69929386.

The product of its (nonzero) digits is 290304, while the sum is 48.

The square root of 209788149 is about 14484.0653478228. The cubic root of 209788149 is about 594.1922509130.

The spelling of 209788149 in words is "two hundred nine million, seven hundred eighty-eight thousand, one hundred forty-nine".