81944957086 has 8 divisors (see below), whose sum is σ = 123028275240. Its totient is φ = 40935532008.

The previous prime is 81944956997. The next prime is 81944957117. The reversal of 81944957086 is 68075944918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81944957086² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18470496 + ... + 18474931.

It is an arithmetic number, because the mean of its divisors is an integer number (15378534405).

Almost surely, 2^81944957086 is an apocalyptic number.

81944957086 is a deficient number, since it is larger than the sum of its proper divisors (41083318154).

81944957086 is a wasteful number, since it uses less digits than its factorization.

81944957086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36946538.

The product of its (nonzero) digits is 17418240, while the sum is 61.

The spelling of 81944957086 in words is "eighty-one billion, nine hundred forty-four million, nine hundred fifty-seven thousand, eighty-six".