81540067 has 6 divisors (see below), whose sum is σ = 94852788. Its totient is φ = 69891444.

The previous prime is 81540031. The next prime is 81540079. The reversal of 81540067 is 76004518.

It is a de Polignac number, because none of the positive numbers 2^k-81540067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81540097) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 831993 + ... + 832090.

It is an arithmetic number, because the mean of its divisors is an integer number (15808798).

Almost surely, 2^81540067 is an apocalyptic number.

81540067 is a deficient number, since it is larger than the sum of its proper divisors (13312721).

81540067 is a wasteful number, since it uses less digits than its factorization.

81540067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1664097 (or 1664090 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 81540067 is about 9029.9538758512. The cubic root of 81540067 is about 433.6343607882.

The spelling of 81540067 in words is "eighty-one million, five hundred forty thousand, sixty-seven".