81965673 has 12 divisors (see below), whose sum is σ = 119328768. Its totient is φ = 54212760.

The previous prime is 81965647. The next prime is 81965699. The reversal of 81965673 is 37656918.

It is a happy number.

81965673 is a `hidden beast` number, since 81 + 9 + 6 + 567 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (81965647) and next prime (81965699).

It is not a de Polignac number, because 81965673 - 2¹² = 81961577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81965633) 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 11 ways as a sum of consecutive naturals, for example, 34713 + ... + 36998.

It is an arithmetic number, because the mean of its divisors is an integer number (9944064).

Almost surely, 2^81965673 is an apocalyptic number.

It is an amenable number.

81965673 is a deficient number, since it is larger than the sum of its proper divisors (37363095).

81965673 is a wasteful number, since it uses less digits than its factorization.

81965673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71844 (or 71841 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 81965673 is about 9053.4895482350. The cubic root of 81965673 is about 434.3875169383.

The spelling of 81965673 in words is "eighty-one million, nine hundred sixty-five thousand, six hundred seventy-three".