81992545 has 8 divisors (see below), whose sum is σ = 98758440. Its totient is φ = 65349120.

The previous prime is 81992527. The next prime is 81992563. The reversal of 81992545 is 54529918.

It is an interprime number because it is at equal distance from previous prime (81992527) and next prime (81992563).

It can be written as a sum of positive squares in 4 ways, for example, as 7273809 + 74718736 = 2697^2 + 8644^2 .

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

It is not a de Polignac number, because 81992545 - 2¹¹ = 81990497 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29136 + ... + 31825.

It is an arithmetic number, because the mean of its divisors is an integer number (12344805).

Almost surely, 2^81992545 is an apocalyptic number.

It is an amenable number.

81992545 is a deficient number, since it is larger than the sum of its proper divisors (16765895).

81992545 is a wasteful number, since it uses less digits than its factorization.

81992545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61235.

The product of its digits is 129600, while the sum is 43.

The square root of 81992545 is about 9054.9734952677. The cubic root of 81992545 is about 434.4349822797.

The spelling of 81992545 in words is "eighty-one million, nine hundred ninety-two thousand, five hundred forty-five".