81242080 has 48 divisors (see below), whose sum is σ = 192568320. Its totient is φ = 32389632.

The previous prime is 81242071. The next prime is 81242087. The reversal of 81242080 is 8024218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81242087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62881 + ... + 64159.

It is an arithmetic number, because the mean of its divisors is an integer number (4011840).

Almost surely, 2^81242080 is an apocalyptic number.

81242080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81242080 is an abundant number, since it is smaller than the sum of its proper divisors (111326240).

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

81242080 is a wasteful number, since it uses less digits than its factorization.

81242080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691 (or 1683 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 81242080 is about 9013.4388553981. The cubic root of 81242080 is about 433.1054791594.

Adding to 81242080 its reverse (8024218), we get a palindrome (89266298).

The spelling of 81242080 in words is "eighty-one million, two hundred forty-two thousand, eighty".