68312905 has 4 divisors (see below), whose sum is σ = 81975492. Its totient is φ = 54650320.

The previous prime is 68312903. The next prime is 68312917. The reversal of 68312905 is 50921386.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16516096 + 51796809 = 4064^2 + 7197^2 .

It is not a de Polignac number, because 68312905 - 2¹ = 68312903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68312903) 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, 6831286 + ... + 6831295.

It is an arithmetic number, because the mean of its divisors is an integer number (20493873).

Almost surely, 2^68312905 is an apocalyptic number.

It is an amenable number.

68312905 is a deficient number, since it is larger than the sum of its proper divisors (13662587).

68312905 is a wasteful number, since it uses less digits than its factorization.

68312905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13662586.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 68312905 is about 8265.1621278714. The cubic root of 68312905 is about 408.7906162198.

The spelling of 68312905 in words is "sixty-eight million, three hundred twelve thousand, nine hundred five".