102189809 has 4 divisors (see below), whose sum is σ = 107568240. Its totient is φ = 96811380.

The previous prime is 102189799. The next prime is 102189817. The reversal of 102189809 is 908981201.

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, and also an emirpimes, since its reverse is a distinct semiprime: 908981201 = 12421 ⋅73181.

It is a cyclic number.

It is not a de Polignac number, because 102189809 - 2⁸ = 102189553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (102189859) 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, 2689187 + ... + 2689224.

It is an arithmetic number, because the mean of its divisors is an integer number (26892060).

Almost surely, 2^102189809 is an apocalyptic number.

102189809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

102189809 is a deficient number, since it is larger than the sum of its proper divisors (5378431).

102189809 is an equidigital number, since it uses as much as digits as its factorization.

102189809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5378430.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 102189809 is about 10108.8975165445. The cubic root of 102189809 is about 467.5225135240.

The spelling of 102189809 in words is "one hundred two million, one hundred eighty-nine thousand, eight hundred nine".