102808009 has 2 divisors, whose sum is σ = 102808010. Its totient is φ = 102808008.

The previous prime is 102808007. The next prime is 102808021. The reversal of 102808009 is 900808201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99440784 + 3367225 = 9972^2 + 1835^2 .

It is a cyclic number.

It is not a de Polignac number, because 102808009 - 2¹ = 102808007 is a prime.

Together with 102808007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (102808007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51404004 + 51404005.

It is an arithmetic number, because the mean of its divisors is an integer number (51404005).

Almost surely, 2^102808009 is an apocalyptic number.

It is an amenable number.

102808009 is a deficient number, since it is larger than the sum of its proper divisors (1).

102808009 is an equidigital number, since it uses as much as digits as its factorization.

102808009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 102808009 is about 10139.4284355678. The cubic root of 102808009 is about 468.4633821399.

The spelling of 102808009 in words is "one hundred two million, eight hundred eight thousand, nine".