68075921 has 4 divisors (see below), whose sum is σ = 68103744. Its totient is φ = 68048100.

The previous prime is 68075873. The next prime is 68075947. The reversal of 68075921 is 12957086.

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: 12957086 = 2 ⋅6478543.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68075921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (68075951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9845 + ... + 15266.

It is an arithmetic number, because the mean of its divisors is an integer number (17025936).

Almost surely, 2^68075921 is an apocalyptic number.

It is an amenable number.

68075921 is a deficient number, since it is larger than the sum of its proper divisors (27823).

68075921 is a wasteful number, since it uses less digits than its factorization.

68075921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27822.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 68075921 is about 8250.8133538458. The cubic root of 68075921 is about 408.3173572906.

The spelling of 68075921 in words is "sixty-eight million, seventy-five thousand, nine hundred twenty-one".