71987678917 has 16 divisors (see below), whose sum is σ = 89903826432. Its totient is φ = 55998699120.

The previous prime is 71987678911. The next prime is 71987678989.

71987678917 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 71987678917 - 2¹¹ = 71987676869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71987678911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 751143 + ... + 841540.

It is an arithmetic number, because the mean of its divisors is an integer number (5618989152).

Almost surely, 2^71987678917 is an apocalyptic number.

71987678917 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

It is an amenable number.

71987678917 is a deficient number, since it is larger than the sum of its proper divisors (17916147515).

71987678917 is a wasteful number, since it uses less digits than its factorization.

71987678917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1593288.

The product of its digits is 74680704, while the sum is 70.

The spelling of 71987678917 in words is "seventy-one billion, nine hundred eighty-seven million, six hundred seventy-eight thousand, nine hundred seventeen".