81718800 has 60 divisors (see below), whose sum is σ = 261776400. Its totient is φ = 21791360.

The previous prime is 81718787. The next prime is 81718807. The reversal of 81718800 is 881718.

It is a tau number, because it is divible by the number of its divisors (60).

It is not an unprimeable number, because it can be changed into a prime (81718807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32850 + ... + 35249.

It is an arithmetic number, because the mean of its divisors is an integer number (4362940).

Almost surely, 2^81718800 is an apocalyptic number.

81718800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81718800 is an abundant number, since it is smaller than the sum of its proper divisors (180057600).

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

81718800 is a wasteful number, since it uses less digits than its factorization.

81718800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68120 (or 68109 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 33.

The square root of 81718800 is about 9039.8451314168. The cubic root of 81718800 is about 433.9509667328.

The spelling of 81718800 in words is "eighty-one million, seven hundred eighteen thousand, eight hundred".