81039996 has 18 divisors (see below), whose sum is σ = 204851192. Its totient is φ = 27013320.

The previous prime is 81039979. The next prime is 81040049. The reversal of 81039996 is 69993018.

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

It is a nialpdrome in base 14.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 1125520 + ... + 1125591.

Almost surely, 2^81039996 is an apocalyptic number.

It is an amenable number.

81039996 is an abundant number, since it is smaller than the sum of its proper divisors (123811196).

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

81039996 is a wasteful number, since it uses less digits than its factorization.

81039996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2251121 (or 2251116 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 81039996 is about 9002.2217257741. The cubic root of 81039996 is about 432.7460744527.

The spelling of 81039996 in words is "eighty-one million, thirty-nine thousand, nine hundred ninety-six".