81546577 has 4 divisors (see below), whose sum is σ = 93196096. Its totient is φ = 69897060.

The previous prime is 81546559. The next prime is 81546593. The reversal of 81546577 is 77564518.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81546577 - 2⁷ = 81546449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81546077) 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, 5824749 + ... + 5824762.

It is an arithmetic number, because the mean of its divisors is an integer number (23299024).

Almost surely, 2^81546577 is an apocalyptic number.

It is an amenable number.

81546577 is a deficient number, since it is larger than the sum of its proper divisors (11649519).

81546577 is a wasteful number, since it uses less digits than its factorization.

81546577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11649518.

The product of its digits is 235200, while the sum is 43.

The square root of 81546577 is about 9030.3143356142. The cubic root of 81546577 is about 433.6459006551.

The spelling of 81546577 in words is "eighty-one million, five hundred forty-six thousand, five hundred seventy-seven".