81724552 has 128 divisors (see below), whose sum is σ = 201600000. Its totient is φ = 30820608.

The previous prime is 81724541. The next prime is 81724561. The reversal of 81724552 is 25542718.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1034449 + ... + 1034527.

It is an arithmetic number, because the mean of its divisors is an integer number (1575000).

Almost surely, 2^81724552 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 81724552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100800000).

81724552 is an abundant number, since it is smaller than the sum of its proper divisors (119875448).

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

81724552 is a wasteful number, since it uses less digits than its factorization.

81724552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 130 counting only the distinct ones).

The product of its digits is 22400, while the sum is 34.

The square root of 81724552 is about 9040.1632728618. The cubic root of 81724552 is about 433.9611481003.

The spelling of 81724552 in words is "eighty-one million, seven hundred twenty-four thousand, five hundred fifty-two".