68121511 has 4 divisors (see below), whose sum is σ = 68414112. Its totient is φ = 67828912.

The previous prime is 68121497. The next prime is 68121523. The reversal of 68121511 is 11512186.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 68121511 - 2¹⁵ = 68088743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68121611) 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, 145951 + ... + 146416.

It is an arithmetic number, because the mean of its divisors is an integer number (17103528).

Almost surely, 2^68121511 is an apocalyptic number.

68121511 is a deficient number, since it is larger than the sum of its proper divisors (292601).

68121511 is a wasteful number, since it uses less digits than its factorization.

68121511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292600.

The product of its digits is 480, while the sum is 25.

The square root of 68121511 is about 8253.5756493777. The cubic root of 68121511 is about 408.4084861073.

Adding to 68121511 its reverse (11512186), we get a palindrome (79633697).

The spelling of 68121511 in words is "sixty-eight million, one hundred twenty-one thousand, five hundred eleven".