81736685 has 8 divisors (see below), whose sum is σ = 98140896. Its totient is φ = 65351440.

The previous prime is 81736673. The next prime is 81736723. The reversal of 81736685 is 58663718.

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

It is not a de Polignac number, because 81736685 - 2¹² = 81732589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7730 + ... + 14940.

It is an arithmetic number, because the mean of its divisors is an integer number (12267612).

Almost surely, 2^81736685 is an apocalyptic number.

It is an amenable number.

81736685 is a deficient number, since it is larger than the sum of its proper divisors (16404211).

81736685 is a wasteful number, since it uses less digits than its factorization.

81736685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9483.

The product of its digits is 241920, while the sum is 44.

The square root of 81736685 is about 9040.8343088456. The cubic root of 81736685 is about 433.9826226345.

The spelling of 81736685 in words is "eighty-one million, seven hundred thirty-six thousand, six hundred eighty-five".