71998861387 has 4 divisors (see below), whose sum is σ = 72095765040. Its totient is φ = 71901957736.

The previous prime is 71998861381. The next prime is 71998861393. The reversal of 71998861387 is 78316889917.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78316889917 = 7 ⋅11188127131.

It is an interprime number because it is at equal distance from previous prime (71998861381) and next prime (71998861393).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71998861387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71998861381) 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, 48450712 + ... + 48452197.

It is an arithmetic number, because the mean of its divisors is an integer number (18023941260).

Almost surely, 2^71998861387 is an apocalyptic number.

71998861387 is a deficient number, since it is larger than the sum of its proper divisors (96903653).

71998861387 is an equidigital number, since it uses as much as digits as its factorization.

71998861387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96903652.

The product of its digits is 36578304, while the sum is 67.

The spelling of 71998861387 in words is "seventy-one billion, nine hundred ninety-eight million, eight hundred sixty-one thousand, three hundred eighty-seven".