81542312 has 8 divisors (see below), whose sum is σ = 152891850. Its totient is φ = 40771152.

The previous prime is 81542297. The next prime is 81542323. The reversal of 81542312 is 21324518.

It can be written as a sum of positive squares in only one way, i.e., 78251716 + 3290596 = 8846^2 + 1814^2 .

It is a tau number, because it is divible by the number of its divisors (8).

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 as a sum of consecutive naturals, namely, 5096387 + ... + 5096402.

Almost surely, 2^81542312 is an apocalyptic number.

It is an amenable number.

81542312 is a deficient number, since it is larger than the sum of its proper divisors (71349538).

81542312 is a wasteful number, since it uses less digits than its factorization.

81542312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10192795 (or 10192791 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 81542312 is about 9030.0781834932. The cubic root of 81542312 is about 433.6383404276.

The spelling of 81542312 in words is "eighty-one million, five hundred forty-two thousand, three hundred twelve".