71312987 has 4 divisors (see below), whose sum is σ = 71423856. Its totient is φ = 71202120.

The previous prime is 71312971. The next prime is 71313007. The reversal of 71312987 is 78921317.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78921317 = 227 ⋅347671.

It is a cyclic number.

It is not a de Polignac number, because 71312987 - 2⁴ = 71312971 is a prime.

It is a super-2 number, since 2×71312987² = 10171084229724338, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71312987.

It is not an unprimeable number, because it can be changed into a prime (71312287) 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, 54464 + ... + 55757.

It is an arithmetic number, because the mean of its divisors is an integer number (17855964).

Almost surely, 2^71312987 is an apocalyptic number.

71312987 is a deficient number, since it is larger than the sum of its proper divisors (110869).

71312987 is a wasteful number, since it uses less digits than its factorization.

71312987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110868.

The product of its digits is 21168, while the sum is 38.

The square root of 71312987 is about 8444.7017117243. The cubic root of 71312987 is about 414.6893441306.

The spelling of 71312987 in words is "seventy-one million, three hundred twelve thousand, nine hundred eighty-seven".