81026886657 has 4 divisors (see below), whose sum is σ = 108035848880. Its totient is φ = 54017924436.

The previous prime is 81026886649. The next prime is 81026886671. The reversal of 81026886657 is 75668862018.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81026886657 - 2³ = 81026886649 is a prime.

It is a super-3 number, since 3×81026886657³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81026886597 and 81026886606.

It is not an unprimeable number, because it can be changed into a prime (81026885657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13504481107 + ... + 13504481112.

It is an arithmetic number, because the mean of its divisors is an integer number (27008962220).

Almost surely, 2^81026886657 is an apocalyptic number.

It is an amenable number.

81026886657 is a deficient number, since it is larger than the sum of its proper divisors (27008962223).

81026886657 is a wasteful number, since it uses less digits than its factorization.

81026886657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27008962222.

The product of its (nonzero) digits is 7741440, while the sum is 57.

The spelling of 81026886657 in words is "eighty-one billion, twenty-six million, eight hundred eighty-six thousand, six hundred fifty-seven".