81726103520 has 96 divisors (see below), whose sum is σ = 201170221056. Its totient is φ = 31340044800.

The previous prime is 81726103519. The next prime is 81726103523. The reversal of 81726103520 is 2530162718.

It is a happy number.

It is a super-4 number, since 4×81726103520⁴ (a number of 45 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81726103523) 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 15 ways as a sum of consecutive naturals, for example, 453725 + ... + 607715.

It is an arithmetic number, because the mean of its divisors is an integer number (2095523136).

Almost surely, 2^81726103520 is an apocalyptic number.

81726103520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81726103520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100585110528).

81726103520 is an abundant number, since it is smaller than the sum of its proper divisors (119444117536).

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

81726103520 is a wasteful number, since it uses less digits than its factorization.

81726103520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154144 (or 154136 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The spelling of 81726103520 in words is "eighty-one billion, seven hundred twenty-six million, one hundred three thousand, five hundred twenty".