68405906 has 8 divisors (see below), whose sum is σ = 103517244. Its totient is φ = 33900160.

The previous prime is 68405903. The next prime is 68405921. The reversal of 68405906 is 60950486.

It can be written as a sum of positive squares in 2 ways, for example, as 67486225 + 919681 = 8215^2 + 959^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 68405906.

It is not an unprimeable number, because it can be changed into a prime (68405903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151115 + ... + 151566.

Almost surely, 2^68405906 is an apocalyptic number.

68405906 is a deficient number, since it is larger than the sum of its proper divisors (35111338).

68405906 is a wasteful number, since it uses less digits than its factorization.

68405906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302796.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 68405906 is about 8270.7862987747. The cubic root of 68405906 is about 408.9760409046.

The spelling of 68405906 in words is "sixty-eight million, four hundred five thousand, nine hundred six".