81736256 has 56 divisors (see below), whose sum is σ = 190414656. Its totient is φ = 34076160.

The previous prime is 81736253. The next prime is 81736261. The reversal of 81736256 is 65263718.

It is a tau number, because it is divible by the number of its divisors (56).

It is not an unprimeable number, because it can be changed into a prime (81736253) 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, 14111 + ... + 19041.

Almost surely, 2^81736256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81736256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95207328).

81736256 is an abundant number, since it is smaller than the sum of its proper divisors (108678400).

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

81736256 is a wasteful number, since it uses less digits than its factorization.

81736256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4987 (or 4977 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 81736256 is about 9040.8105831280. The cubic root of 81736256 is about 433.9818633717.

It can be divided in two parts, 817 and 36256, that added together give a palindrome (37073).

The spelling of 81736256 in words is "eighty-one million, seven hundred thirty-six thousand, two hundred fifty-six".