81393498 has 20 divisors (see below), whose sum is σ = 182382090. Its totient is φ = 27131112.

The previous prime is 81393457. The next prime is 81393523. The reversal of 81393498 is 89439318.

It can be written as a sum of positive squares in only one way, i.e., 63728289 + 17665209 = 7983^2 + 4203^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 251053 + ... + 251376.

Almost surely, 2^81393498 is an apocalyptic number.

81393498 is an abundant number, since it is smaller than the sum of its proper divisors (100988592).

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

81393498 is a wasteful number, since it uses less digits than its factorization.

81393498 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502443 (or 502434 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 81393498 is about 9021.8345141108. The cubic root of 81393498 is about 433.3743844081.

The spelling of 81393498 in words is "eighty-one million, three hundred ninety-three thousand, four hundred ninety-eight".