81436673 has 8 divisors (see below), whose sum is σ = 83118528. Its totient is φ = 79760304.

The previous prime is 81436661. The next prime is 81436723. The reversal of 81436673 is 37663418.

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 81436673 - 2⁴ = 81436657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81436633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42686 + ... + 44552.

It is an arithmetic number, because the mean of its divisors is an integer number (10389816).

Almost surely, 2^81436673 is an apocalyptic number.

It is an amenable number.

81436673 is a deficient number, since it is larger than the sum of its proper divisors (1681855).

81436673 is a wasteful number, since it uses less digits than its factorization.

81436673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2743.

The product of its digits is 72576, while the sum is 38.

The square root of 81436673 is about 9024.2270029072. The cubic root of 81436673 is about 433.4509983560.

The spelling of 81436673 in words is "eighty-one million, four hundred thirty-six thousand, six hundred seventy-three".