71986913 has 4 divisors (see below), whose sum is σ = 72154368. Its totient is φ = 71819460.

The previous prime is 71986909. The next prime is 71986919. The reversal of 71986913 is 31968917.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31968917 = 647 ⋅49411.

It is a cyclic number.

It is not a de Polignac number, because 71986913 - 2² = 71986909 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71986919) 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 3 ways as a sum of consecutive naturals, for example, 83081 + ... + 83942.

It is an arithmetic number, because the mean of its divisors is an integer number (18038592).

Almost surely, 2^71986913 is an apocalyptic number.

It is an amenable number.

71986913 is a deficient number, since it is larger than the sum of its proper divisors (167455).

71986913 is a wasteful number, since it uses less digits than its factorization.

71986913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167454.

The product of its digits is 81648, while the sum is 44.

The square root of 71986913 is about 8484.5101803227. The cubic root of 71986913 is about 415.9915574747.

The spelling of 71986913 in words is "seventy-one million, nine hundred eighty-six thousand, nine hundred thirteen".