81966023914 has 16 divisors (see below), whose sum is σ = 123096584520. Its totient is φ = 40933857280.

The previous prime is 81966023873. The next prime is 81966023927. The reversal of 81966023914 is 41932066918.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 81500543289 + 465480625 = 285483^2 + 21575^2 .

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, 8826954 + ... + 8836234.

Almost surely, 2^81966023914 is an apocalyptic number.

81966023914 is a deficient number, since it is larger than the sum of its proper divisors (41130560606).

81966023914 is a wasteful number, since it uses less digits than its factorization.

81966023914 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14105.

The product of its (nonzero) digits is 559872, while the sum is 49.

The spelling of 81966023914 in words is "eighty-one billion, nine hundred sixty-six million, twenty-three thousand, nine hundred fourteen".