81446400 has 360 divisors, whose sum is σ = 336411504. Its totient is φ = 18432000.

The previous prime is 81446383. The next prime is 81446461. The reversal of 81446400 is 464418.

81446400 is a `hidden beast` number, since 8 + 14 + 4 + 640 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 806350 + ... + 806450.

Almost surely, 2^81446400 is an apocalyptic number.

81446400 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 81446400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168205752).

81446400 is an abundant number, since it is smaller than the sum of its proper divisors (254965104).

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

81446400 is a wasteful number, since it uses less digits than its factorization.

81446400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 81446400 is about 9024.7659249423. The cubic root of 81446400 is about 433.4682551596.

The spelling of 81446400 in words is "eighty-one million, four hundred forty-six thousand, four hundred".