68243905 has 4 divisors (see below), whose sum is σ = 81892692. Its totient is φ = 54595120.

The previous prime is 68243897. The next prime is 68243909. The reversal of 68243905 is 50934286.

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 22316176 + 45927729 = 4724^2 + 6777^2 .

It is not a de Polignac number, because 68243905 - 2³ = 68243897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68243909) 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, 6824386 + ... + 6824395.

It is an arithmetic number, because the mean of its divisors is an integer number (20473173).

Almost surely, 2^68243905 is an apocalyptic number.

It is an amenable number.

68243905 is a deficient number, since it is larger than the sum of its proper divisors (13648787).

68243905 is a wasteful number, since it uses less digits than its factorization.

68243905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13648786.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 68243905 is about 8260.9869265119. The cubic root of 68243905 is about 408.6529357693.

The spelling of 68243905 in words is "sixty-eight million, two hundred forty-three thousand, nine hundred five".