68521906 has 8 divisors (see below), whose sum is σ = 105289884. Its totient is φ = 33425280.

The previous prime is 68521903. The next prime is 68521907. The reversal of 68521906 is 60912586.

It can be written as a sum of positive squares in 2 ways, for example, as 67387681 + 1134225 = 8209^2 + 1065^2 .

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

It is not an unprimeable number, because it can be changed into a prime (68521903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417735 + ... + 417898.

Almost surely, 2^68521906 is an apocalyptic number.

68521906 is a deficient number, since it is larger than the sum of its proper divisors (36767978).

68521906 is a wasteful number, since it uses less digits than its factorization.

68521906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835676.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 68521906 is about 8277.7959626944. The cubic root of 68521906 is about 409.2070854271.

The spelling of 68521906 in words is "sixty-eight million, five hundred twenty-one thousand, nine hundred six".