81838080 has 240 divisors, whose sum is σ = 298835040. Its totient is φ = 21233664.

The previous prime is 81838069. The next prime is 81838093. The reversal of 81838080 is 8083818.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2211822 + ... + 2211858.

It is an arithmetic number, because the mean of its divisors is an integer number (1245146).

Almost surely, 2^81838080 is an apocalyptic number.

81838080 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 81838080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149417520).

81838080 is an abundant number, since it is smaller than the sum of its proper divisors (216996960).

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

81838080 is an equidigital number, since it uses as much as digits as its factorization.

81838080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 81838080 is about 9046.4401838513. The cubic root of 81838080 is about 434.1620014325.

The spelling of 81838080 in words is "eighty-one million, eight hundred thirty-eight thousand, eighty".