81946800 has 360 divisors, whose sum is σ = 327416544. Its totient is φ = 18800640.

The previous prime is 81946789. The next prime is 81946801. The reversal of 81946800 is 864918.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81946801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 795549 + ... + 795651.

Almost surely, 2^81946800 is an apocalyptic number.

81946800 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 81946800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163708272).

81946800 is an abundant number, since it is smaller than the sum of its proper divisors (245469744).

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

81946800 is a wasteful number, since it uses less digits than its factorization.

81946800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81946800 is about 9052.4471829445. The cubic root of 81946800 is about 434.3541744238.

The spelling of 81946800 in words is "eighty-one million, nine hundred forty-six thousand, eight hundred".