68511987 has 20 divisors (see below), whose sum is σ = 104282640. Its totient is φ = 44810064.

The previous prime is 68511931. The next prime is 68512001. The reversal of 68511987 is 78911586.

It is not a de Polignac number, because 68511987 - 2⁶ = 68511923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (68511907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3687 + ... + 12272.

It is an arithmetic number, because the mean of its divisors is an integer number (5214132).

Almost surely, 2^68511987 is an apocalyptic number.

68511987 is a deficient number, since it is larger than the sum of its proper divisors (35770653).

68511987 is a wasteful number, since it uses less digits than its factorization.

68511987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16024 (or 16015 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 68511987 is about 8277.1968080987. The cubic root of 68511987 is about 409.1873393284.

The spelling of 68511987 in words is "sixty-eight million, five hundred eleven thousand, nine hundred eighty-seven".