68705809 has 4 divisors (see below), whose sum is σ = 68927040. Its totient is φ = 68484580.

The previous prime is 68705783. The next prime is 68705831. The reversal of 68705809 is 90850786.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68705809 - 2⁹ = 68705297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68705839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110149 + ... + 110770.

It is an arithmetic number, because the mean of its divisors is an integer number (17231760).

Almost surely, 2^68705809 is an apocalyptic number.

It is an amenable number.

68705809 is a deficient number, since it is larger than the sum of its proper divisors (221231).

68705809 is a wasteful number, since it uses less digits than its factorization.

68705809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221230.

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 68705809 is about 8288.8967299635. The cubic root of 68705809 is about 409.5728428478.

The spelling of 68705809 in words is "sixty-eight million, seven hundred five thousand, eight hundred nine".