81475200 has 384 divisors, whose sum is σ = 318729600. Its totient is φ = 20275200.

The previous prime is 81475189. The next prime is 81475201. The reversal of 81475200 is 257418.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81475201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1987180 + ... + 1987220.

It is an arithmetic number, because the mean of its divisors is an integer number (830025).

Almost surely, 2^81475200 is an apocalyptic number.

81475200 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 81475200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159364800).

81475200 is an abundant number, since it is smaller than the sum of its proper divisors (237254400).

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

81475200 is a wasteful number, since it uses less digits than its factorization.

81475200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 74 counting only the distinct ones).

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

The square root of 81475200 is about 9026.3613931639. The cubic root of 81475200 is about 433.5193415778.

The spelling of 81475200 in words is "eighty-one million, four hundred seventy-five thousand, two hundred".