83971565 has 4 divisors (see below), whose sum is σ = 100765884. Its totient is φ = 67177248.

The previous prime is 83971541. The next prime is 83971577. The reversal of 83971565 is 56517938.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56517938 = 2 ⋅28258969.

It can be written as a sum of positive squares in 2 ways, for example, as 53743561 + 30228004 = 7331^2 + 5498^2 .

It is a cyclic number.

It is not a de Polignac number, because 83971565 - 2¹⁰ = 83970541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 8397152 + ... + 8397161.

It is an arithmetic number, because the mean of its divisors is an integer number (25191471).

Almost surely, 2^83971565 is an apocalyptic number.

It is an amenable number.

83971565 is a deficient number, since it is larger than the sum of its proper divisors (16794319).

83971565 is a wasteful number, since it uses less digits than its factorization.

83971565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16794318.

The product of its digits is 226800, while the sum is 44.

The square root of 83971565 is about 9163.6000021825. The cubic root of 83971565 is about 437.9024910994.

The spelling of 83971565 in words is "eighty-three million, nine hundred seventy-one thousand, five hundred sixty-five".