81804977801 has 8 divisors (see below), whose sum is σ = 83820867144. Its totient is φ = 79790071680.

The previous prime is 81804977797. The next prime is 81804977833. The reversal of 81804977801 is 10877940818.

It can be written as a sum of positive squares in 4 ways, for example, as 4545995776 + 77258982025 = 67424^2 + 277955^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81804977801 - 2² = 81804977797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81804977861) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 75926 + ... + 411551.

It is an arithmetic number, because the mean of its divisors is an integer number (10477608393).

Almost surely, 2^81804977801 is an apocalyptic number.

It is an amenable number.

81804977801 is a deficient number, since it is larger than the sum of its proper divisors (2015889343).

81804977801 is a wasteful number, since it uses less digits than its factorization.

81804977801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491611.

The product of its (nonzero) digits is 903168, while the sum is 53.

The spelling of 81804977801 in words is "eighty-one billion, eight hundred four million, nine hundred seventy-seven thousand, eight hundred one".