81676563 has 8 divisors (see below), whose sum is σ = 108945408. Its totient is φ = 54429384.

The previous prime is 81676549. The next prime is 81676583. The reversal of 81676563 is 36567618.

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

It is not a de Polignac number, because 81676563 - 2⁵ = 81676531 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (81676583) 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, 8470 + ... + 15332.

It is an arithmetic number, because the mean of its divisors is an integer number (13618176).

Almost surely, 2^81676563 is an apocalyptic number.

81676563 is a deficient number, since it is larger than the sum of its proper divisors (27268845).

81676563 is a wasteful number, since it uses less digits than its factorization.

81676563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10833.

The product of its digits is 181440, while the sum is 42.

The square root of 81676563 is about 9037.5086721950. The cubic root of 81676563 is about 433.8761901996.

The spelling of 81676563 in words is "eighty-one million, six hundred seventy-six thousand, five hundred sixty-three".