81530198 has 8 divisors (see below), whose sum is σ = 129489192. Its totient is φ = 38367136.

The previous prime is 81530179. The next prime is 81530201. The reversal of 81530198 is 89103518.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 1198940 + ... + 1199007.

It is an arithmetic number, because the mean of its divisors is an integer number (16186149).

Almost surely, 2^81530198 is an apocalyptic number.

81530198 is a deficient number, since it is larger than the sum of its proper divisors (47958994).

81530198 is a wasteful number, since it uses less digits than its factorization.

81530198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2397966.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 81530198 is about 9029.4074002672. The cubic root of 81530198 is about 433.6168654621.

It can be divided in two parts, 815 and 30198, that added together give a palindrome (31013).

The spelling of 81530198 in words is "eighty-one million, five hundred thirty thousand, one hundred ninety-eight".