81206853600 has 144 divisors (see below), whose sum is σ = 264421544688. Its totient is φ = 21647523840.

The previous prime is 81206853593. The next prime is 81206853617. The reversal of 81206853600 is 635860218.

It is a happy number.

It is a super-2 number, since 2×81206853600² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11125152 + ... + 11132448.

It is an arithmetic number, because the mean of its divisors is an integer number (1836260727).

Almost surely, 2^81206853600 is an apocalyptic number.

81206853600 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 81206853600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132210772344).

81206853600 is an abundant number, since it is smaller than the sum of its proper divisors (183214691088).

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

81206853600 is a wasteful number, since it uses less digits than its factorization.

81206853600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11957 (or 11944 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 81206853600 in words is "eighty-one billion, two hundred six million, eight hundred fifty-three thousand, six hundred".