81956263976 has 16 divisors (see below), whose sum is σ = 153672724800. Its totient is φ = 40976870704.

The previous prime is 81956263973. The next prime is 81956263999. The reversal of 81956263976 is 67936265918.

It is not an unprimeable number, because it can be changed into a prime (81956263973) 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, 154961 + ... + 433503.

It is an arithmetic number, because the mean of its divisors is an integer number (9604545300).

Almost surely, 2^81956263976 is an apocalyptic number.

It is an amenable number.

81956263976 is a deficient number, since it is larger than the sum of its proper divisors (71716460824).

81956263976 is a wasteful number, since it uses less digits than its factorization.

81956263976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315328 (or 315324 counting only the distinct ones).

The product of its digits is 29393280, while the sum is 62.

The spelling of 81956263976 in words is "eighty-one billion, nine hundred fifty-six million, two hundred sixty-three thousand, nine hundred seventy-six".