209564097 has 24 divisors (see below), whose sum is σ = 290284992. Its totient is φ = 134416800.

The previous prime is 209564087. The next prime is 209564099. The reversal of 209564097 is 790465902.

It is not a de Polignac number, because 209564097 - 2⁷ = 209563969 is a prime.

It is a super-2 number, since 2×209564097² = 87834221502850818, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (209564099) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1650048 + ... + 1650174.

It is an arithmetic number, because the mean of its divisors is an integer number (12095208).

Almost surely, 2^209564097 is an apocalyptic number.

It is an amenable number.

209564097 is a deficient number, since it is larger than the sum of its proper divisors (80720895).

209564097 is an equidigital number, since it uses as much as digits as its factorization.

209564097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 209564097 is about 14476.3288509207. The cubic root of 209564097 is about 593.9806447683.

The spelling of 209564097 in words is "two hundred nine million, five hundred sixty-four thousand, ninety-seven".