81724032 has 256 divisors, whose sum is σ = 277603200. Its totient is φ = 23445504.

The previous prime is 81724021. The next prime is 81724043. The reversal of 81724032 is 23042718.

It is an interprime number because it is at equal distance from previous prime (81724021) and next prime (81724043).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81723987 and 81724005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 763723 + ... + 763829.

Almost surely, 2^81724032 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 81724032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138801600).

81724032 is an abundant number, since it is smaller than the sum of its proper divisors (195879168).

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

81724032 is a wasteful number, since it uses less digits than its factorization.

81724032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 81724032 is about 9040.1345122736. The cubic root of 81724032 is about 433.9602276903.

The spelling of 81724032 in words is "eighty-one million, seven hundred twenty-four thousand, thirty-two".