81600080 has 20 divisors (see below), whose sum is σ = 189720372. Its totient is φ = 32640000.

The previous prime is 81600073. The next prime is 81600137. The reversal of 81600080 is 8000618.

It can be written as a sum of positive squares in 2 ways, for example, as 39037504 + 42562576 = 6248^2 + 6524^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 509921 + ... + 510080.

Almost surely, 2^81600080 is an apocalyptic number.

81600080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81600080 is an abundant number, since it is smaller than the sum of its proper divisors (108120292).

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

81600080 is a wasteful number, since it uses less digits than its factorization.

81600080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020014 (or 1020008 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 81600080 is about 9033.2762605823. The cubic root of 81600080 is about 433.7407187953.

Adding to 81600080 its reverse (8000618), we get a palindrome (89600698).

The spelling of 81600080 in words is "eighty-one million, six hundred thousand, eighty".