102187809 has 12 divisors (see below), whose sum is σ = 149627556. Its totient is φ = 67191552.

The previous prime is 102187807. The next prime is 102187829. The reversal of 102187809 is 908781201.

It can be written as a sum of positive squares in 2 ways, for example, as 63250209 + 38937600 = 7953^2 + 6240^2 .

It is not a de Polignac number, because 102187809 - 2¹ = 102187807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (102187807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77112 + ... + 78425.

It is an arithmetic number, because the mean of its divisors is an integer number (12468963).

Almost surely, 2^102187809 is an apocalyptic number.

It is an amenable number.

102187809 is a deficient number, since it is larger than the sum of its proper divisors (47439747).

102187809 is a wasteful number, since it uses less digits than its factorization.

102187809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155616 (or 155613 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 102187809 is about 10108.7985933047. The cubic root of 102187809 is about 467.5194634771.

The spelling of 102187809 in words is "one hundred two million, one hundred eighty-seven thousand, eight hundred nine".