81120080 has 40 divisors (see below), whose sum is σ = 196808832. Its totient is φ = 31036544.

The previous prime is 81120079. The next prime is 81120113. The reversal of 81120080 is 8002118.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (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 7 ways as a sum of consecutive naturals, for example, 20204 + ... + 23883.

Almost surely, 2^81120080 is an apocalyptic number.

81120080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81120080 is an abundant number, since it is smaller than the sum of its proper divisors (115688752).

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

81120080 is a wasteful number, since it uses less digits than its factorization.

81120080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44123 (or 44117 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 81120080 is about 9006.6686405130. The cubic root of 81120080 is about 432.8885745715. Note that the first 3 decimals are identical.

Adding to 81120080 its reverse (8002118), we get a palindrome (89122198).

The spelling of 81120080 in words is "eighty-one million, one hundred twenty thousand, eighty".