81536403200 has 108 divisors (see below), whose sum is σ = 230646227280. Its totient is φ = 27955322880.

The previous prime is 81536403191. The next prime is 81536403257. The reversal of 81536403200 is 230463518.

It is a Harshad number since it is a multiple of its sum of digits (32).

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 11 ways as a sum of consecutive naturals, for example, 865205 + ... + 954804.

Almost surely, 2^81536403200 is an apocalyptic number.

81536403200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81536403200 is an abundant number, since it is smaller than the sum of its proper divisors (149109824080).

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

81536403200 is a wasteful number, since it uses less digits than its factorization.

81536403200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820042 (or 1820023 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 81536403200 its reverse (230463518), we get a palindrome (81766866718).

The spelling of 81536403200 in words is "eighty-one billion, five hundred thirty-six million, four hundred three thousand, two hundred".