68815209 has 8 divisors (see below), whose sum is σ = 91984032. Its totient is φ = 45761600.

The previous prime is 68815183. The next prime is 68815211. The reversal of 68815209 is 90251886.

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 68815209 - 2⁷ = 68815081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (68815249) 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, 27399 + ... + 29804.

It is an arithmetic number, because the mean of its divisors is an integer number (11498004).

Almost surely, 2^68815209 is an apocalyptic number.

It is an amenable number.

68815209 is a deficient number, since it is larger than the sum of its proper divisors (23168823).

68815209 is a wasteful number, since it uses less digits than its factorization.

68815209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57607.

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 68815209 is about 8295.4932945546. The cubic root of 68815209 is about 409.7901146648.

It can be divided in two parts, 6881 and 5209, that added together give a triangular number (12090 = T₁₅₅).

The spelling of 68815209 in words is "sixty-eight million, eight hundred fifteen thousand, two hundred nine".