81329796 has 18 divisors (see below), whose sum is σ = 205583742. Its totient is φ = 27109920.

The previous prime is 81329777. The next prime is 81329839. The reversal of 81329796 is 69792318.

It can be written as a sum of positive squares in only one way, i.e., 50126400 + 31203396 = 7080^2 + 5586^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×81329796² = 13229071434803232, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1129545 + ... + 1129616.

It is an arithmetic number, because the mean of its divisors is an integer number (11421319).

Almost surely, 2^81329796 is an apocalyptic number.

It is an amenable number.

81329796 is an abundant number, since it is smaller than the sum of its proper divisors (124253946).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81329796 is a wasteful number, since it uses less digits than its factorization.

81329796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2259171 (or 2259166 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 81329796 is about 9018.3033881102. The cubic root of 81329796 is about 433.2612958489.

The spelling of 81329796 in words is "eighty-one million, three hundred twenty-nine thousand, seven hundred ninety-six".