81725503860 has 576 divisors, whose sum is σ = 352438055424. Its totient is φ = 14752972800.

The previous prime is 81725503823. The next prime is 81725503861. The reversal of 81725503860 is 6830552718.

81725503860 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 550 + 38 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81725503861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3049720 + ... + 3076400.

It is an arithmetic number, because the mean of its divisors is an integer number (611871624).

Almost surely, 2^81725503860 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 81725503860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176219027712).

81725503860 is an abundant number, since it is smaller than the sum of its proper divisors (270712551564).

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

81725503860 is a wasteful number, since it uses less digits than its factorization.

81725503860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26744 (or 26739 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

It can be divided in two parts, 81725 and 503860, that added together give a palindrome (585585).

The spelling of 81725503860 in words is "eighty-one billion, seven hundred twenty-five million, five hundred three thousand, eight hundred sixty".