81219353600 has 264 divisors, whose sum is σ = 251009493888. Its totient is φ = 25314508800.

The previous prime is 81219353597. The next prime is 81219353627. The reversal of 81219353600 is 635391218.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1950599 + ... + 1991801.

Almost surely, 2^81219353600 is an apocalyptic number.

81219353600 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 81219353600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125504746944).

81219353600 is an abundant number, since it is smaller than the sum of its proper divisors (169790140288).

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

81219353600 is a wasteful number, since it uses less digits than its factorization.

81219353600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41251 (or 41228 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 81219353600 in words is "eighty-one billion, two hundred nineteen million, three hundred fifty-three thousand, six hundred".