81611015686 has 16 divisors (see below), whose sum is σ = 124673774400. Its totient is φ = 40055117608.

The previous prime is 81611015659. The next prime is 81611015693. The reversal of 81611015686 is 68651011618.

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, 425716 + ... + 586903.

It is an arithmetic number, because the mean of its divisors is an integer number (7792110900).

Almost surely, 2^81611015686 is an apocalyptic number.

81611015686 is a deficient number, since it is larger than the sum of its proper divisors (43062758714).

81611015686 is a wasteful number, since it uses less digits than its factorization.

81611015686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013363.

The product of its (nonzero) digits is 69120, while the sum is 43.

The spelling of 81611015686 in words is "eighty-one billion, six hundred eleven million, fifteen thousand, six hundred eighty-six".