81928299 has 4 divisors (see below), whose sum is σ = 109237736. Its totient is φ = 54618864.

The previous prime is 81928261. The next prime is 81928303. The reversal of 81928299 is 99282918.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81928299 - 2⁹ = 81927787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81928229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13654714 + ... + 13654719.

It is an arithmetic number, because the mean of its divisors is an integer number (27309434).

Almost surely, 2^81928299 is an apocalyptic number.

81928299 is a deficient number, since it is larger than the sum of its proper divisors (27309437).

81928299 is a wasteful number, since it uses less digits than its factorization.

81928299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27309436.

The product of its digits is 186624, while the sum is 48.

The square root of 81928299 is about 9051.4252468879. The cubic root of 81928299 is about 434.3214841442.

The spelling of 81928299 in words is "eighty-one million, nine hundred twenty-eight thousand, two hundred ninety-nine".