81617536 has 192 divisors, whose sum is σ = 223992000. Its totient is φ = 29352960.

The previous prime is 81617531. The next prime is 81617551. The reversal of 81617536 is 63571618.

It is a super-3 number, since 3×81617536³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Its product of digits (30240) is a multiple of the sum of its prime factors (72).

It is a junction number, because it is equal to n+sod(n) for n = 81617495 and 81617504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81617531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6278266 + ... + 6278278.

It is an arithmetic number, because the mean of its divisors is an integer number (1166625).

Almost surely, 2^81617536 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 81617536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111996000).

81617536 is an abundant number, since it is smaller than the sum of its proper divisors (142374464).

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

81617536 is a wasteful number, since it uses less digits than its factorization.

81617536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 33 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The square root of 81617536 is about 9034.2424142813. The cubic root of 81617536 is about 433.7716453914.

The spelling of 81617536 in words is "eighty-one million, six hundred seventeen thousand, five hundred thirty-six".