81692665 has 8 divisors (see below), whose sum is σ = 102293568. Its totient is φ = 62512560.

The previous prime is 81692617. The next prime is 81692669. The reversal of 81692665 is 56629618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81692665 - 2¹⁹ = 81168377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81692669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355071 + ... + 355300.

It is an arithmetic number, because the mean of its divisors is an integer number (12786696).

Almost surely, 2^81692665 is an apocalyptic number.

It is an amenable number.

81692665 is a deficient number, since it is larger than the sum of its proper divisors (20600903).

81692665 is a wasteful number, since it uses less digits than its factorization.

81692665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710399.

The product of its digits is 155520, while the sum is 43.

The square root of 81692665 is about 9038.3994711453. The cubic root of 81692665 is about 433.9047002769.

The spelling of 81692665 in words is "eighty-one million, six hundred ninety-two thousand, six hundred sixty-five".