81288492 has 24 divisors (see below), whose sum is σ = 200830896. Its totient is φ = 25502208.

The previous prime is 81288481. The next prime is 81288511. The reversal of 81288492 is 29488218.

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, 199033 + ... + 199440.

It is an arithmetic number, because the mean of its divisors is an integer number (8367954).

Almost surely, 2^81288492 is an apocalyptic number.

It is an amenable number.

81288492 is an abundant number, since it is smaller than the sum of its proper divisors (119542404).

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

81288492 is a wasteful number, since it uses less digits than its factorization.

81288492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398497 (or 398495 counting only the distinct ones).

The product of its digits is 73728, while the sum is 42.

The square root of 81288492 is about 9016.0130878343. The cubic root of 81288492 is about 433.1879383353.

The spelling of 81288492 in words is "eighty-one million, two hundred eighty-eight thousand, four hundred ninety-two".