81672800 has 72 divisors (see below), whose sum is σ = 217532952. Its totient is φ = 29696000.

The previous prime is 81672797. The next prime is 81672821. The reversal of 81672800 is 827618.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 4160 + ... + 13440.

It is an arithmetic number, because the mean of its divisors is an integer number (3021291).

Almost surely, 2^81672800 is an apocalyptic number.

81672800 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 81672800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108766476).

81672800 is an abundant number, since it is smaller than the sum of its proper divisors (135860152).

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

81672800 is a wasteful number, since it uses less digits than its factorization.

81672800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312 (or 9299 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 81672800 is about 9037.3004818917. The cubic root of 81672800 is about 433.8695269206.

The spelling of 81672800 in words is "eighty-one million, six hundred seventy-two thousand, eight hundred".