81802619218 has 8 divisors (see below), whose sum is σ = 122707245312. Its totient is φ = 40900204116.

The previous prime is 81802619207. The next prime is 81802619221. The reversal of 81802619218 is 81291620818.

It is a happy number.

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

It is a super-3 number, since 3×81802619218³ (a number of 34 digits) contains 333 as substring.

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 3 ways as a sum of consecutive naturals, for example, 456930 + ... + 610237.

It is an arithmetic number, because the mean of its divisors is an integer number (15338405664).

Almost surely, 2^81802619218 is an apocalyptic number.

81802619218 is a deficient number, since it is larger than the sum of its proper divisors (40904626094).

81802619218 is a wasteful number, since it uses less digits than its factorization.

81802619218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105496.

The product of its (nonzero) digits is 110592, while the sum is 46.

The spelling of 81802619218 in words is "eighty-one billion, eight hundred two million, six hundred nineteen thousand, two hundred eighteen".