102120209 has 4 divisors (see below), whose sum is σ = 103851120. Its totient is φ = 100389300.

The previous prime is 102120203. The next prime is 102120301. The reversal of 102120209 is 902021201.

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 102120209 - 2²⁴ = 85342993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (102120203) 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, 865367 + ... + 865484.

It is an arithmetic number, because the mean of its divisors is an integer number (25962780).

Almost surely, 2^102120209 is an apocalyptic number.

It is an amenable number.

102120209 is a deficient number, since it is larger than the sum of its proper divisors (1730911).

102120209 is an equidigital number, since it uses as much as digits as its factorization.

102120209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1730910.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 102120209 is about 10105.4544182832. The cubic root of 102120209 is about 467.4163484785.

The spelling of 102120209 in words is "one hundred two million, one hundred twenty thousand, two hundred nine".