68536721 has 8 divisors (see below), whose sum is σ = 75161088. Its totient is φ = 61978000.

The previous prime is 68536697. The next prime is 68536751. The reversal of 68536721 is 12763586.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68536721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68536751) 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 7 ways as a sum of consecutive naturals, for example, 14210 + ... + 18411.

It is an arithmetic number, because the mean of its divisors is an integer number (9395136).

Almost surely, 2^68536721 is an apocalyptic number.

It is an amenable number.

68536721 is a deficient number, since it is larger than the sum of its proper divisors (6624367).

68536721 is a wasteful number, since it uses less digits than its factorization.

68536721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32823.

The product of its digits is 60480, while the sum is 38.

The square root of 68536721 is about 8278.6907781364. The cubic root of 68536721 is about 409.2365746151.

The spelling of 68536721 in words is "sixty-eight million, five hundred thirty-six thousand, seven hundred twenty-one".