81020686013 has 8 divisors (see below), whose sum is σ = 83029442496. Its totient is φ = 79013484000.

The previous prime is 81020686009. The next prime is 81020686031. The reversal of 81020686013 is 31068602018.

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 81020686013 - 2² = 81020686009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81020686073) 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, 282731 + ... + 491912.

It is an arithmetic number, because the mean of its divisors is an integer number (10378680312).

Almost surely, 2^81020686013 is an apocalyptic number.

It is an amenable number.

81020686013 is a deficient number, since it is larger than the sum of its proper divisors (2008756483).

81020686013 is a wasteful number, since it uses less digits than its factorization.

81020686013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777235.

The product of its (nonzero) digits is 13824, while the sum is 35.

The spelling of 81020686013 in words is "eighty-one billion, twenty million, six hundred eighty-six thousand, thirteen".