81996247 has 8 divisors (see below), whose sum is σ = 85323456. Its totient is φ = 78735072.

The previous prime is 81996221. The next prime is 81996283. The reversal of 81996247 is 74269918.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81996247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81996197 and 81996206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81996947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13968 + ... + 18949.

It is an arithmetic number, because the mean of its divisors is an integer number (10665432).

Almost surely, 2^81996247 is an apocalyptic number.

81996247 is a deficient number, since it is larger than the sum of its proper divisors (3327209).

81996247 is a wasteful number, since it uses less digits than its factorization.

81996247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33017.

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

The square root of 81996247 is about 9055.1779110076. The cubic root of 81996247 is about 434.4415204924.

The spelling of 81996247 in words is "eighty-one million, nine hundred ninety-six thousand, two hundred forty-seven".