209561489 has 8 divisors (see below), whose sum is σ = 214797792. Its totient is φ = 204341760.

The previous prime is 209561467. The next prime is 209561503. The reversal of 209561489 is 984165902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209561489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209561449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23762 + ... + 31364.

It is an arithmetic number, because the mean of its divisors is an integer number (26849724).

Almost surely, 2^209561489 is an apocalyptic number.

It is an amenable number.

209561489 is a deficient number, since it is larger than the sum of its proper divisors (5236303).

209561489 is an equidigital number, since it uses as much as digits as its factorization.

209561489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8287.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 209561489 is about 14476.2387725541. The cubic root of 209561489 is about 593.9781807522.

The spelling of 209561489 in words is "two hundred nine million, five hundred sixty-one thousand, four hundred eighty-nine".