68738721 has 16 divisors (see below), whose sum is σ = 94711680. Its totient is φ = 44320640.

The previous prime is 68738707. The next prime is 68738731. The reversal of 68738721 is 12783786.

It is a cyclic number.

It is not a de Polignac number, because 68738721 - 2⁵ = 68738689 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (68738731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8245 + ... + 14333.

It is an arithmetic number, because the mean of its divisors is an integer number (5919480).

Almost surely, 2^68738721 is an apocalyptic number.

It is an amenable number.

68738721 is a deficient number, since it is larger than the sum of its proper divisors (25972959).

68738721 is a wasteful number, since it uses less digits than its factorization.

68738721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6216.

The product of its digits is 112896, while the sum is 42.

The square root of 68738721 is about 8290.8817986991. The cubic root of 68738721 is about 409.6382313488.

The spelling of 68738721 in words is "sixty-eight million, seven hundred thirty-eight thousand, seven hundred twenty-one".