81736686 has 12 divisors (see below), whose sum is σ = 177096192. Its totient is φ = 27245556.

The previous prime is 81736673. The next prime is 81736723. The reversal of 81736686 is 68663718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2270446 + ... + 2270481.

It is an arithmetic number, because the mean of its divisors is an integer number (14758016).

Almost surely, 2^81736686 is an apocalyptic number.

81736686 is an abundant number, since it is smaller than the sum of its proper divisors (95359506).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81736686 is a wasteful number, since it uses less digits than its factorization.

81736686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4540935 (or 4540932 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 81736686 is about 9040.8343641502. The cubic root of 81736686 is about 433.9826244043.

The spelling of 81736686 in words is "eighty-one million, seven hundred thirty-six thousand, six hundred eighty-six".