68121515 has 64 divisors (see below), whose sum is σ = 109209600. Its totient is φ = 40360320.

The previous prime is 68121497. The next prime is 68121523. The reversal of 68121515 is 51512186.

It is a de Polignac number, because none of the positive numbers 2^k-68121515 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 433817 + ... + 433973.

It is an arithmetic number, because the mean of its divisors is an integer number (1706400).

Almost surely, 2^68121515 is an apocalyptic number.

68121515 is a deficient number, since it is larger than the sum of its proper divisors (41088085).

68121515 is a wasteful number, since it uses less digits than its factorization.

68121515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 203 counting only the distinct ones).

The product of its digits is 2400, while the sum is 29.

The square root of 68121515 is about 8253.5758916969. The cubic root of 68121515 is about 408.4084941010.

The spelling of 68121515 in words is "sixty-eight million, one hundred twenty-one thousand, five hundred fifteen".