102210809 has 8 divisors (see below), whose sum is σ = 102983400. Its totient is φ = 101441536.

The previous prime is 102210803. The next prime is 102210821. The reversal of 102210809 is 908012201.

It can be written as a sum of positive squares in 4 ways, for example, as 28302400 + 73908409 = 5320^2 + 8597^2 .

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-102210809 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 (102210803) 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, 104129 + ... + 105105.

It is an arithmetic number, because the mean of its divisors is an integer number (12872925).

Almost surely, 2^102210809 is an apocalyptic number.

It is an amenable number.

102210809 is a deficient number, since it is larger than the sum of its proper divisors (772591).

102210809 is an equidigital number, since it uses as much as digits as its factorization.

102210809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1659.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 102210809 is about 10109.9361521228. The cubic root of 102210809 is about 467.5545366139.

The spelling of 102210809 in words is "one hundred two million, two hundred ten thousand, eight hundred nine".