81164686 has 16 divisors (see below), whose sum is σ = 123171840. Its totient is φ = 40110520.

The previous prime is 81164669. The next prime is 81164687. The reversal of 81164686 is 68646118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81164687) 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, 67785 + ... + 68971.

It is an arithmetic number, because the mean of its divisors is an integer number (7698240).

Almost surely, 2^81164686 is an apocalyptic number.

81164686 is a deficient number, since it is larger than the sum of its proper divisors (42007154).

81164686 is a wasteful number, since it uses less digits than its factorization.

81164686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1559.

The product of its digits is 55296, while the sum is 40.

The square root of 81164686 is about 9009.1445764845. The cubic root of 81164686 is about 432.9679050717.

The spelling of 81164686 in words is "eighty-one million, one hundred sixty-four thousand, six hundred eighty-six".