81088486421 has 4 divisors (see below), whose sum is σ = 81999593100. Its totient is φ = 80177379744.

The previous prime is 81088486351. The next prime is 81088486447. The reversal of 81088486421 is 12468488018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12071416900 + 69017069521 = 109870^2 + 262711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81088486421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81088486421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81088486471) by changing a digit.

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, 455553206 + ... + 455553383.

It is an arithmetic number, because the mean of its divisors is an integer number (20499898275).

Almost surely, 2^81088486421 is an apocalyptic number.

It is an amenable number.

81088486421 is a deficient number, since it is larger than the sum of its proper divisors (911106679).

81088486421 is an equidigital number, since it uses as much as digits as its factorization.

81088486421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911106678.

The product of its (nonzero) digits is 786432, while the sum is 50.

The spelling of 81088486421 in words is "eighty-one billion, eighty-eight million, four hundred eighty-six thousand, four hundred twenty-one".