81947296 has 24 divisors (see below), whose sum is σ = 161711424. Its totient is φ = 40877760.

The previous prime is 81947237. The next prime is 81947297. The reversal of 81947296 is 69274918.

It is not an unprimeable number, because it can be changed into a prime (81947297) 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, 12051 + ... + 17581.

It is an arithmetic number, because the mean of its divisors is an integer number (6737976).

Almost surely, 2^81947296 is an apocalyptic number.

It is an amenable number.

81947296 is a deficient number, since it is larger than the sum of its proper divisors (79764128).

81947296 is a wasteful number, since it uses less digits than its factorization.

81947296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6004 (or 5996 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The square root of 81947296 is about 9052.4745788099. The cubic root of 81947296 is about 434.3550507616.

The spelling of 81947296 in words is "eighty-one million, nine hundred forty-seven thousand, two hundred ninety-six".