81798160 has 80 divisors (see below), whose sum is σ = 195987456. Its totient is φ = 31739904.

The previous prime is 81798151. The next prime is 81798161. The reversal of 81798160 is 6189718.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (81798161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 644017 + ... + 644143.

Almost surely, 2^81798160 is an apocalyptic number.

81798160 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 81798160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97993728).

81798160 is an abundant number, since it is smaller than the sum of its proper divisors (114189296).

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

81798160 is a wasteful number, since it uses less digits than its factorization.

81798160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 81798160 is about 9044.2335219741. The cubic root of 81798160 is about 434.0913962979.

The spelling of 81798160 in words is "eighty-one million, seven hundred ninety-eight thousand, one hundred sixty".