81404160 has 288 divisors, whose sum is σ = 291392640. Its totient is φ = 19267584.

The previous prime is 81404123. The next prime is 81404161. The reversal of 81404160 is 6140418.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 81404160.

It is not an unprimeable number, because it can be changed into a prime (81404161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1893099 + ... + 1893141.

It is an arithmetic number, because the mean of its divisors is an integer number (1011780).

Almost surely, 2^81404160 is an apocalyptic number.

81404160 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 81404160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145696320).

81404160 is an abundant number, since it is smaller than the sum of its proper divisors (209988480).

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

81404160 is a wasteful number, since it uses less digits than its factorization.

81404160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 81404160 is about 9022.4253945378. The cubic root of 81404160 is about 433.3933066237.

Adding to 81404160 its reverse (6140418), we get a palindrome (87544578).

The spelling of 81404160 in words is "eighty-one million, four hundred four thousand, one hundred sixty".