81686585454 has 16 divisors (see below), whose sum is σ = 172983357648. Its totient is φ = 25627164032.

The previous prime is 81686585353. The next prime is 81686585473. The reversal of 81686585454 is 45458568618.

It is a super-2 number, since 2×81686585454² (a number of 23 digits) contains 22 as substring.

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, 400424337 + ... + 400424540.

It is an arithmetic number, because the mean of its divisors is an integer number (10811459853).

Almost surely, 2^81686585454 is an apocalyptic number.

81686585454 is an abundant number, since it is smaller than the sum of its proper divisors (91296772194).

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

81686585454 is a wasteful number, since it uses less digits than its factorization.

81686585454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800848899.

The product of its digits is 36864000, while the sum is 60.

The spelling of 81686585454 in words is "eighty-one billion, six hundred eighty-six million, five hundred eighty-five thousand, four hundred fifty-four".