81540692 has 12 divisors (see below), whose sum is σ = 147616980. Its totient is φ = 39364416.

The previous prime is 81540691. The next prime is 81540707. The reversal of 81540692 is 29604518.

It can be written as a sum of positive squares in 2 ways, for example, as 33709636 + 47831056 = 5806^2 + 6916^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540691) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 351353 + ... + 351584.

It is an arithmetic number, because the mean of its divisors is an integer number (12301415).

Almost surely, 2^81540692 is an apocalyptic number.

It is an amenable number.

81540692 is a deficient number, since it is larger than the sum of its proper divisors (66076288).

81540692 is a wasteful number, since it uses less digits than its factorization.

81540692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 702970 (or 702968 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 81540692 is about 9029.9884828276. The cubic root of 81540692 is about 433.6354687130.

The spelling of 81540692 in words is "eighty-one million, five hundred forty thousand, six hundred ninety-two".