81547200 has 252 divisors, whose sum is σ = 331652880. Its totient is φ = 18616320.

The previous prime is 81547187. The next prime is 81547201. The reversal of 81547200 is 274518.

It is a tau number, because it is divible by the number of its divisors (252).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81547201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 100396 + ... + 101204.

Almost surely, 2^81547200 is an apocalyptic number.

81547200 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 81547200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165826440).

81547200 is an abundant number, since it is smaller than the sum of its proper divisors (250105680).

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

81547200 is a wasteful number, since it uses less digits than its factorization.

81547200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844 (or 826 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 81547200 is about 9030.3488304716. The cubic root of 81547200 is about 433.6470049758.

The spelling of 81547200 in words is "eighty-one million, five hundred forty-seven thousand, two hundred".