209981089 has 4 divisors (see below), whose sum is σ = 210235824. Its totient is φ = 209726356.

The previous prime is 209981077. The next prime is 209981111. The reversal of 209981089 is 980189902.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 209981089 - 2¹¹ = 209979041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209981029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126127 + ... + 127780.

It is an arithmetic number, because the mean of its divisors is an integer number (52558956).

Almost surely, 2^209981089 is an apocalyptic number.

It is an amenable number.

209981089 is a deficient number, since it is larger than the sum of its proper divisors (254735).

209981089 is an equidigital number, since it uses as much as digits as its factorization.

209981089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254734.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 209981089 is about 14490.7242400095. The cubic root of 209981089 is about 594.3743525966.

It can be divided in two parts, 20998 and 1089, that multiplied together give a palindrome (22866822).

The spelling of 209981089 in words is "two hundred nine million, nine hundred eighty-one thousand, eighty-nine".