81739198 has 8 divisors (see below), whose sum is σ = 122679000. Its totient is φ = 40846200.

The previous prime is 81739187. The next prime is 81739201. The reversal of 81739198 is 89193718.

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 (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6948 + ... + 14551.

It is an arithmetic number, because the mean of its divisors is an integer number (15334875).

Almost surely, 2^81739198 is an apocalyptic number.

81739198 is a deficient number, since it is larger than the sum of its proper divisors (40939802).

81739198 is a wasteful number, since it uses less digits than its factorization.

81739198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23402.

The product of its digits is 108864, while the sum is 46.

The square root of 81739198 is about 9040.9732883136. The cubic root of 81739198 is about 433.9870701975.

It can be divided in two parts, 8173 and 9198, that added together give a palindrome (17371).

The spelling of 81739198 in words is "eighty-one million, seven hundred thirty-nine thousand, one hundred ninety-eight".