81517296 has 120 divisors (see below), whose sum is σ = 255598720. Its totient is φ = 21869568.

The previous prime is 81517283. The next prime is 81517309. The reversal of 81517296 is 69271518.

81517296 is a nontrivial binomial coefficient, being equal to C(12769, 2).

It is an interprime number because it is at equal distance from previous prime (81517283) and next prime (81517309).

Its product of digits (30240) is a multiple of the sum of its prime divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 721336 + ... + 721448.

Almost surely, 2^81517296 is an apocalyptic number.

81517296 is the 12768-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81517296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127799360).

81517296 is an abundant number, since it is smaller than the sum of its proper divisors (174081424).

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

81517296 is a wasteful number, since it uses less digits than its factorization.

81517296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263 (or 144 counting only the distinct ones).

The product of its digits is 30240, while the sum is 39.

The square root of 81517296 is about 9028.6929286581. The cubic root of 81517296 is about 433.5939912386.

The spelling of 81517296 in words is "eighty-one million, five hundred seventeen thousand, two hundred ninety-six".