102278909 has 6 divisors (see below), whose sum is σ = 104503614. Its totient is φ = 100100600.

The previous prime is 102278903. The next prime is 102278929. The reversal of 102278909 is 909872201.

It can be written as a sum of positive squares in only one way, i.e., 79744900 + 22534009 = 8930^2 + 4747^2 .

It is not a de Polignac number, because 102278909 - 2²⁰ = 101230333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102278903) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20942 + ... + 25359.

It is an arithmetic number, because the mean of its divisors is an integer number (17417269).

Almost surely, 2^102278909 is an apocalyptic number.

It is an amenable number.

102278909 is a deficient number, since it is larger than the sum of its proper divisors (2224705).

102278909 is an frugal number, since it uses more digits than its factorization.

102278909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46395 (or 46348 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 102278909 is about 10113.3035651067. The cubic root of 102278909 is about 467.6583527544.

The spelling of 102278909 in words is "one hundred two million, two hundred seventy-eight thousand, nine hundred nine".