81814800 has 120 divisors (see below), whose sum is σ = 271232640. Its totient is φ = 21056000.

The previous prime is 81814793. The next prime is 81814801. The reversal of 81814800 is 841818.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×81814800² = 13387322998080000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81814801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33625 + ... + 35975.

It is an arithmetic number, because the mean of its divisors is an integer number (2260272).

Almost surely, 2^81814800 is an apocalyptic number.

81814800 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 81814800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135616320).

81814800 is an abundant number, since it is smaller than the sum of its proper divisors (189417840).

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

81814800 is a wasteful number, since it uses less digits than its factorization.

81814800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2401 (or 2390 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 30.

The square root of 81814800 is about 9045.1533983675. The cubic root of 81814800 is about 434.1208296865.

The spelling of 81814800 in words is "eighty-one million, eight hundred fourteen thousand, eight hundred".