68695721 has 4 divisors (see below), whose sum is σ = 70911744. Its totient is φ = 66479700.

The previous prime is 68695709. The next prime is 68695763. The reversal of 68695721 is 12759686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12759686 = 2 ⋅6379843.

It is a cyclic number.

It is not a de Polignac number, because 68695721 - 2²⁶ = 1586857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68695021) 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, 1107965 + ... + 1108026.

It is an arithmetic number, because the mean of its divisors is an integer number (17727936).

Almost surely, 2^68695721 is an apocalyptic number.

It is an amenable number.

68695721 is a deficient number, since it is larger than the sum of its proper divisors (2216023).

68695721 is a wasteful number, since it uses less digits than its factorization.

68695721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2216022.

The product of its digits is 181440, while the sum is 44.

The square root of 68695721 is about 8288.2881827311. The cubic root of 68695721 is about 409.5527961534.

The spelling of 68695721 in words is "sixty-eight million, six hundred ninety-five thousand, seven hundred twenty-one".