81081725008 has 30 divisors (see below), whose sum is σ = 162699763694. Its totient is φ = 39142895232.

The previous prime is 81081725003. The next prime is 81081725071. The reversal of 81081725008 is 80052718018.

It can be written as a sum of positive squares in 3 ways, for example, as 14307030544 + 66774694464 = 119612^2 + 258408^2 .

It is a super-2 number, since 2×81081725008² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81081725003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2999391 + ... + 3026302.

Almost surely, 2^81081725008 is an apocalyptic number.

It is an amenable number.

81081725008 is an abundant number, since it is smaller than the sum of its proper divisors (81618038686).

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

81081725008 is a wasteful number, since it uses less digits than its factorization.

81081725008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6025759 (or 6025724 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 40.

The spelling of 81081725008 in words is "eighty-one billion, eighty-one million, seven hundred twenty-five thousand, eight".