81286949656 has 32 divisors (see below), whose sum is σ = 172002171600. Its totient is φ = 35674522240.

The previous prime is 81286949647. The next prime is 81286949687. The reversal of 81286949656 is 65694968218.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 15923575 + ... + 15928678.

Almost surely, 2^81286949656 is an apocalyptic number.

It is an amenable number.

81286949656 is an abundant number, since it is smaller than the sum of its proper divisors (90715221944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81286949656 is a wasteful number, since it uses less digits than its factorization.

81286949656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31852299 (or 31852295 counting only the distinct ones).

The product of its digits is 44789760, while the sum is 64.

The spelling of 81286949656 in words is "eighty-one billion, two hundred eighty-six million, nine hundred forty-nine thousand, six hundred fifty-six".