81965597 has 8 divisors (see below), whose sum is σ = 93788352. Its totient is φ = 70171200.

The previous prime is 81965579. The next prime is 81965627. The reversal of 81965597 is 79556918.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81965597 - 2¹⁶ = 81900061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81965557) 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 7 ways as a sum of consecutive naturals, for example, 479 + ... + 12812.

It is an arithmetic number, because the mean of its divisors is an integer number (11723544).

Almost surely, 2^81965597 is an apocalyptic number.

It is an amenable number.

81965597 is a deficient number, since it is larger than the sum of its proper divisors (11822755).

81965597 is a wasteful number, since it uses less digits than its factorization.

81965597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14179.

The product of its digits is 680400, while the sum is 50.

The square root of 81965597 is about 9053.4853509574. The cubic root of 81965597 is about 434.3873826810.

The spelling of 81965597 in words is "eighty-one million, nine hundred sixty-five thousand, five hundred ninety-seven".