81576649 has 8 divisors (see below), whose sum is σ = 101706048. Its totient is φ = 63566160.

The previous prime is 81576643. The next prime is 81576689. The reversal of 81576649 is 94667518.

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

It is not a de Polignac number, because 81576649 - 2⁹ = 81576137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81576599 and 81576608.

It is not an unprimeable number, because it can be changed into a prime (81576643) 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 7 ways as a sum of consecutive naturals, for example, 529642 + ... + 529795.

It is an arithmetic number, because the mean of its divisors is an integer number (12713256).

Almost surely, 2^81576649 is an apocalyptic number.

It is an amenable number.

81576649 is a deficient number, since it is larger than the sum of its proper divisors (20129399).

81576649 is a wasteful number, since it uses less digits than its factorization.

81576649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059455.

The product of its digits is 362880, while the sum is 46.

The square root of 81576649 is about 9031.9792404544. The cubic root of 81576649 is about 433.6991994255.

The spelling of 81576649 in words is "eighty-one million, five hundred seventy-six thousand, six hundred forty-nine".