30681209 has 8 divisors (see below), whose sum is σ = 34985160. Its totient is φ = 26654976.

The previous prime is 30681193. The next prime is 30681221. The reversal of 30681209 is 90218603.

It can be written as a sum of positive squares in 4 ways, for example, as 1951609 + 28729600 = 1397^2 + 5360^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 30681209 - 2⁴ = 30681193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30681269) 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, 69194 + ... + 69635.

It is an arithmetic number, because the mean of its divisors is an integer number (4373145).

Almost surely, 2^30681209 is an apocalyptic number.

It is an amenable number.

30681209 is a deficient number, since it is larger than the sum of its proper divisors (4303951).

30681209 is a wasteful number, since it uses less digits than its factorization.

30681209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138859.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 30681209 is about 5539.0621047250. The cubic root of 30681209 is about 313.0575314363.

The spelling of 30681209 in words is "thirty million, six hundred eighty-one thousand, two hundred nine".